• Spatial Information Research
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• v.15 no.2
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• pp.135-146
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• 2007

The purpose of this study was to ascertain and analyze environmental factors of subgenus Lycoctonum in Korea for conservation and management of rare high land plant species by GIS. We derived the habitat model of Lycoctonum from GPS coordination, habitat factors and digital topology maps. Suitable altitude fur the subgenus Lycoctonum is from 470m to 1320m, and northern slopes(between 15.5 and 36 degrees) are ideal for the Lycoctonum populations. In addition to altitude, slope and aspect, deciduous forest and approximation to water source were found as important factor. Using GIS and the Lycoctonum habitat model, we overlaid elevation, aspect, slope and land cover layers and analyzed buffer from the water source on two topology maps, Yang-Soo and Mock-Dong. After making prediction map for Lycoctonum habitat, we verified the existence of Lycoctonum populations on the predicted sites through field survey. Through this research, we're convinced that GIS software is powerful tool for plants conservation, such as finding unknown habitat or selecting alternative habitat.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.7
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• pp.653-659
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• 2016

This paper proposes an ultra-wideband Log-Periodic Dipole Array(LPDA) antenna for the feeder of a reflector antenna to be used for airborne spinning direction-finding and detecting wideband signals. To obtain the ultra-wideband characteristics over the 20:1 bandwidth from S to Ka band, the radiation elements of the antenna were printed on a substrate and a wedge-typed dielectric supporter with robust structure was inserted between the substrates. Also, the center portion of the supporter was replaced by a styrofoam material to reduce the supporter weight. The 5-dB return loss of the designed LPDA antenna showed ultra-wideband characteristics, which are 37.57:1(1.09~40.95 GHz) in the simulation and 33.85:1(1.31~44.35 GHz) in the measurement. We achieved the required gains of 5.78 dBi in the simulation and 5.76 dBi in the measurement in the operating band. The proposed robust, light-weight, and ultra-wideband LPDA antenna confirmed that it can be applied for airborne applications.

• Korean Journal of Social Welfare
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• v.68 no.2
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• pp.27-51
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• 2016

This paper is about the NOOMP(Not Out of My Pocket) phenomenon, the inconsistent welfare attitude for an expansion of welfare system and increase of financial resources. By analyzing the scale and influential factors of the NOOMP to the main welfare programs, focusing on the class, gender, and age group, the paper tries to investigate the relationship between the NOOMP and the inherent stratification structure of each programs. This paper uses the Additional Survey of Welfare Attitude in 2013 Korea Welfare Panel Survey. As a result of analysis, low level of NOOMP phenomenon has been observed in welfare programs for whole society members such as health policies, pension, employment policies, compared to those of targeted programs for the poor, aged, or disabled. In addition, high probability of each group of 'low incomer', 'female', and '20s or less'to the NOOMP phenomenon has been appeared, therefore, high relevance of the NOOMP and the stratification structure of welfare programs have been confirmed. These results indicate that the transition to the universal welfare programs and the improvement of welfare programs for more equal structure are needed to reduce the NOOMP phenomenon.

• Physical Therapy Korea
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• v.2 no.2
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• pp.1-8
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• 1995

이 논문의 주목적은 정상인을 대상으로 각기 다른 3가지의 (체중의 1.5 %, 3.0 %, 9.0 %) 부하를 통해서 자세의 불균형을 유발시켰을 때 나타나는 postural movement patterns을 기술하기 위한 연구이다. 연구대상의 허리중심에 체중부하를 주어 균형이 뒤로 이동하게 하여, surface EMG(표면 근전도)를 통하여 Tibialis anterior(Ta), Gastrocnernius(Gc), Quadriceps femoris(Qc), Hamstring(Ha), Rectus abdominalis(Ab)와 Paraspinalis(Pa) 근육들의 motor recruitment pattern(운동회집형태)를 측정하였다. 그리고 비디오 촬영은 고관절, 슬관절, 족관절의 움직임을 보기 위해 사용하였다. 특히 근전도 (EMG)는 자세반응 검사에 있어 첫 근반응(근수축) 경과시간(FR)과 분절간격간의 (ID)시간을 조사하는데 사용되었다. 이 연구의 결과는 4가지 중요한 사실을 전해주고 있다. 첫 번째로서, 연구대상자에게 체중의 1.5 %의 부하를 적용하였을 때 Ta가 가장 먼저 수축을 시작하였고(FR:$88{\pm}19.4$ ms) 발목과 대퇴사이의 분절 간격간(ID)의 평균은 +9.3 ms였다. 또한 족관절의 변화가 가장 뚜렷하여 Nashner(1985)의 족기전을 뒷받침하고 있다. 둘째로는 연구대상자에게 체중의 3.0 %의 부하를 주었을 때 Qc와 Ab근육이 원위부에서 근위부 순서로 수축하였고, 첫 번째 근육수축시간은 ($82{\pm}39.2$ ms)였다. 그리고 이때 분절간격의 평균은 +8.3ms 이였고 Ta는 거의 반응하지 않았다. 족관절과 슬관절에 비해 고관절의 변화가 가장 현저하게 나타났고, 이 또한 Nashner의 고관절 기전과 같은 현상을 보였다. 셋째로 연구 대상자에게 체중의 9.0 % 부하를 허리에 적용하였을 때 근수축은 근위부에서 원위부 순서를 이루어졌다. 즉 Ab,Qc, Ta, Ps순으로 근수축 되었다. Ab가 처음으로 수축하여 첫 반응(FR)은 $73{\pm}3.2$ ms 이였고 슬관절과 고관절의 변화가 가장 뚜렷하였다. 넷째로 연구 대상자에게 체중의 9.0 %부하를 적용하였을 때, 균형을 잡기 위해 뒷걸음치는 것이 관찰되었고 이때 근수축 순서는 Ta,Ab.Ps,Qc,Hs였다. 이 결과는 Nasher의 결과와 불일치하였다. 이상과 같은 결과에서 연구대상자의 자세운동형태(postural movement patterns)는 각기 다른 부하 정도와 시간에 따라 합성적으로 이루어지는 것으로 보여졌다. 특히, 자세운동형태는 부하의 적용위치와 연구대상자의 최근의 경험에 영향을 받은 것으로 밝혀졌다. 결론적으로 말하면 자세운동형태는 중앙신경계의 제한적(한정적) 명령 시스템에 의해서 움직임(movement)이 발생하기 전에 조직된다는 Nashner의 가설을 뒷받침하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.301-306
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• 2016

During the initial stage of propulsion shaft design, the shaft alignment process includes a thorough consideration of lateral vibration to verify the operational safety of the shaft. However, a theoretical method for analyzing forced lateral vibrations has not been clearly established. The methods currently used in classification societies and international standards can only ensure a sufficient margin to avoid the blade-passing frequency resonance speed outside the range of ${\pm}20%$ of the maximum continuous rating (MCR) for the engine. Typically, in shaft alignment analyses, longer center distances between the support bearings promote affirmative results, but the blade order resonance speed can approach the lower limit for lateral vibration. Therefore, this matter requires careful attention by engineers, and a verification of the theoretical analysis by experimental measurements is highly desirable. In this study, both theoretical and experimental analyses were conducted using strain gauges under two draught conditions of vessels used as 50,000-DWT oil/chemical tankers, introduced recently as eco-friendly ships. Based on the analyses, the influence of the lateral vibration on the shafting system and the system's reliability was reviewed.

• Journal of the Korean School Mathematics Society
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• v.13 no.4
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• pp.525-548
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• 2010

How to enhance the ability of underachieve students are unsolved problems for mathematics teachers despite of their best efforts to teach them. The purpose of this study is to explore the effectiveness of mathematical journal writing as a method of improving the mathematical attitudes and achievements for underachieve students. Seven students whose performances were below 40% on the final exam in the 1st semester were recruited in order to gather empirical data. Before journal writing procedures, the subjects' characteristics, learning styles and mathematical attitudes were investigated through personal interview and mathematical attitude test. After six-week journal writing, follow-up survey and mathematical attitude test were conducted. The results of this research are as follows: Mathematical journal writing had a positive effect to underachieve students on improving confidence in mathematics and a positive influence on active and effective learning attitude. And mathematical journal writing had an effect on improvement in their mathematics achievement comparing first semester's final exam with second semester's mid-term exam. Finally mathematical journal writing contributes positively to the relationship between students and their teacher.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1693-1705
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• 2013

To restore old aqueduct in Korea which is a irrigation bridge to supply water in paddy field area, it is needed to estimate approximate costs of restoration because the basic design for estimation of construction costs is often ruled out in current system. In this paper, estimating models of construction costs were developed on the basis of performance data for restoration of RC aqueduct bridges since 2003. The regression analysis (RA) model and case-based reasoning (CBR) model for the estimation of construction costs were developed respectively. Error rate of simple RA model was lower than that of multiple RA model. CBR model using genetic algorithm (GA) has been applied in the estimation of construction costs. In the model three factors like attribute weight, attribute deviation and rank of case similarity were optimized. Especially, error rate of estimated construction costs decreased since limit ranges of the attribute weights were applied. The results showed that error rates between RA model and CBR models were inconsiderable statistically. It is expected that the proposed estimating method of approximate costs of aqueduct restoration will be utilized to support quick decision making in phased rehabilitation project.

• Journal of Life Science
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• v.18 no.9
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• pp.1284-1289
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• 2008

This research was conducted to elucidate the optimum conditions for the maesil vinegar fermentation by Acetobacter sp. SK-7 using evolutionary operation (EVOP)-factorial design technique. The acidity of maesil vinegar was effected by ethanol concentration in the range of 3-7% (r=-0.5166), and glucose concentration in the range of 0.1-0.5% (r=-0.5061). The acidity of maesil vinegar was not effected by differentiation of temperature in the range of 24-$33^{\circ}C$ (r=0.1082). The optimum maesil vinegar fermentation by Acetobacter sp. SK-7 as determined by the EVOP-factorial design technique was obtained at an fermentation temperature of $30^{\circ}C$, ethanol concentration of 4%, glucose concentration of 0.2%. Furthermore, the acidity of vinegar increase from an initial acidity of 5.4% to 6.365% in the third set that is nearly 1.0% by EVOP-factorial design technique

• The Mathematical Education
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• v.59 no.3
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• pp.237-254
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• 2020

The current study investigated the relationships between mathematical knowledge for teaching and the mathematical quality in instruction in order to gain insight about teacher education for secondary teachers in South Korea. We collected and analyzed twelve high school teachers' scores of the multiple-choice assessment for mathematical knowledge for teaching developed by the Measures of Effective Teaching project. Their instruction was video recorded and analyzed with the mathematical quality in instruction developed by the Learning Mathematics for Teaching project. We also interviewed the teachers about how they planned and assessed their instruction by themselves in order to gain information about their intention and interpretation about instruction. There was a statistically significant and positive association between the levels of mathematical knowledge for teaching and the mathematical quality in instruction. Among three dimensions of the mathematical quality in instruction, mathematical richness seemed most relevant to mathematical knowledge for teaching because subject matter knowledge plays an important role in mathematical knowledge for teaching. Furthermore, working with students and mathematics as well as students participation were critical to decide the quality of instruction. Based on these findings, the current study discussed offering opportunities to learn mathematical knowledge for teaching and philosophy about how teachers need to consider students in high schools particularly in terms of constructivism.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.94-100
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• 2012

The passive control by vertical splitter plate of fluid force acting on a square prism near a plane wall was studied by measuring of fluid force on the prism and by visualization of the flow field using PIV. The hight of the splitter plate was 10% of the square width. The experimental parameters were the attaching position of vertical splitter plate and the space ratios G/B to the prism height. Time variation of vorticity was most remarkable at 3.0B(B: prism height) position toward wake direction from the center of the prism. The point of inflection of average lift coefficient and Strouhal number on the prism were represented at the space ratio G/B=0.4~0.6 for the prism having vertical splitter plate. The drag of the prism was reduced average 5.0% with the space ratios by attaching the vertical splitter plate at the upper and rear corner on the prism. In this case, the size of the separated region on the upside of the prism was smaller than that of prism having no the splitter plate.