• Journal of Advanced Marine Engineering and Technology
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• v.36 no.2
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• pp.267-275
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• 2012

In this study, normal wind load and blast wind load are modeled mathematical. And the periodical torque and bending moments transmitted to the main shaft of wind turbine are investigated. A normal wind model assumed, of which the wind velocity is increased according to the height from ground. The average values and the harmonic terms of the transmitted moments are studied on the wind direction of range $-45^{\circ}{\sim}45^{\circ}$ and the bending moment characteristics are examined, which is regarded as the main source of the misalignment of gear train. In normal wind load case, excitation frequency is 3X (X : Rotor speed). When the wind direction is $+22.5^{\circ}$, the horizontal axis of bending moment occur the 50% of main torque. This result leads to edge contact of gear teeth by shaft elastic deformation. In blast wind load case, excitation frequency are 3X,6X,9X. Additional, in the (+) direction of wind load, relative harmonic percentage is increase.

• Journal of The Korean Association of Information Education
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• v.10 no.1
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• pp.13-22
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• 2006

Students should be able to find information and resources using the Internet. Also students need to have composite intellectual abilities to select information, convert to knowledge and communicate it to other people. However, most school and classroom homepages provide students with information but not contents that help them produce knowledge. This lowers the rate of connection to homepage. Thus, the purpose of this study is to develop and apply homepage, which helps students make knowledge from comprehended and interpreted information(Knowledge.Sharing Technique; KST). In this study we use 'WIKI KST' and 'Q&A KST' to share knowledge. WIKI KST is 'an encyclopedia that we make,' which means that students upload their prior knowledge or knowledge produced from comprehended and interpreted information and create new knowledge to be added to their own knowledge and others'. As a result, the abilities to comprehend and interpret acquired information are improved and the ability to change implicit knowledge to explicit knowledge is also improved. Students create new knowledge to share their knowledge and, as a result, the rate to connection to homepage gets higher.

• Journal of the Korean School Mathematics Society
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• v.23 no.1
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• pp.159-177
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• 2020

Education researchers have been continuously interested in the teacher's ability to design lessons and conducted various studies in order to improve the teacher's professionalism in determining the quality of school instruction. So, this study explored the change of instructional design through the lesson reflection of pre-service mathematics teachers who participated in practicum settings. As a result, in the lesson plan prepared by pre-service mathematics teachers, the motivation to induce learning in the introduction stage, to present the learning contents in the development stage, and to reconstruct the formative evaluation of the closing stage was the highest rate. And the categories of the reconstructed contents appeared intensively in terms of curriculum contents and teaching and learning methods. This result can be attributed to the lack of experience in designing and performing lessons by pre-service mathematics teachers, so it suggests that the opportunity to design and conduct classes that take into account the practical aspects of education should be provided in the preparation process for pre-service mathematics teachers.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.1
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• pp.49-55
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• 2008

The face extraction is very important to provide the images of the roads and road sides without the problem of privacy. For face extraction form roadside images, we detected the skin color area by using HSI and YCrCb color models. Efficient skin color detection was achieved by using these two models. We used a connectivity and intensity difference for grouping, skin color regions further we applied shape conditions (rate, area, number and oval condition) and determined face candidate regions. We applied thresholds to region, and determined the region as the face if black part was over 5% of the whole regions. As the result of the experiment 28 faces has been extracted among 38 faces had problem of privacy. The reasons which the face was not extracted were the effect of shadow of the face, and the background objects. Also objects with the color similar to the face were falsely extracted. For improvement, we need to adjust the threshold.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.2
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• pp.187-198
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• 2017

In this study, we analyzed the accessibility of open platform Android mobile banking applications, based on Korean mobile application accessibility KS standard, Section 508 technical standard of Rehabilitation Act, and European BBC guidelines. Experimental result showed that there are no mobile banking applications of 8 commercial banks in Korea that satisfy all guidelines of three standards. Typical violations included missing alternative text, keyboard focus violations, control size and spacing non-compliance, and low contrast ratio. These violations are fatal in that they make the accessibility of the blind, the disabled and the low vision and the elderly impossible. The reason that mobile banking applications do not comply with accessibility is that mobile application developers and providers have low awareness of accessibility and do not know how to implement accessibility properly. Comparing Korea mobile application accessibility guidelines with the revised standard of the Section 508 of Rehabilitation Act and the BBC standard, many guidelines are missing. Also, evaluation criteria are ambiguous and abstract, making it difficult for developers to refer specifically. Therefore, improving mobile application accessibility requires developer and government efforts and complementation of standards.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.244-244
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• 2017

2015년 국토교통부(영산강홍수통제소)에서는 물 순환 과정의 규명에 이용되는 증발산량 자료의 제공을 목적으로 무안지역에 플럭스 타워를 설치하여 운영하고 있다. 무안 플럭스 타워는 에디공분산 방법을 이용하여 증발산량 자료를 관측하는 방식으로, 본 연구에서는 무안 관측소에서 생산된 자료의 정상성 검토를 위하여 2015년과 2016년 운영 결과를 비교 분석하였다. 무안관측소의 2015년도 연 증발산량은 615.8mm(연 강수량 대비 56.0%)로 나타났으며, 2016년도 연 증발산량은 721.5mm(연 강수량 대비 49.5%)로 나타났다. 연 증발산량은 전년대비 약 100mm 증가하는 양상을 보였으며, 강수량 대비 비율은 6.5% 감소하는 것으로 분석되었다. 2015년 대비 2016년 무강우일수는 6일 증가 하였으나, 실제 순복사에너지는 $18,320w/m^2$ 감소하는 것으로 나타났다. 실제 이 차이는 2개년 평균치의 약 2% 내외 수준으로 예년대비 순복사에너지는 거의 비슷한 것으로 분석되었다. 복합적 요인에 의해 정량적 크기가 결정되는 증발산량의 특성상 추가적인 분석이 필요하나, 2016년의 경우 전년대비 증가한 강우의 영향이 지배적이였던 것으로 검토되었다(2015강수량 : 1,099mm, 2016강수량 : 1,457mm). 월별 증발산량 비교 분석결과 정량적인 차이는 존재했으나 전년과 마찬가지로 1월부터 증발산량이 증가하여 8월에 최대 증발산량을 보인 후 감소하는 형태를 나타냈으며, 5월과 6월이 증발산량이 역전되는 양상도 동일하게 나타났다. 이는 남부지역 모내기 시기인 5월경 관개용수(Irrigation water) 공급에 따른 유입원의 증가와 함께 5월 대비 6월(장마철) 흐린날(Cloudy condition) 증가에 따른 상대적인 순복사에너지(5월: 약20만$w/m^2$, 6월: 약17만$w/m^2$)의 감소가 주 원인이였던 것으로 검토되었다. 이를 통해 볼 때 무안 증발산량 자료는 추가적인 경년변화 연구가 필요하겠으나, 국가통계자료로써 유의미한 자료로 판단되며, 향후 증발산량에 대한 지속적인 연구 및 관측망의 확대를 통해 국가 이수관련 정책수립에 유용한 자료로 이용 될 수 있을것으로 판단된다.

• The Journal of the Korea Contents Association
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• v.19 no.3
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• pp.328-335
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• 2019

Korea is entering into an "Aging Society" rapidly. In this currency, the Elderly Supporting Problems is emerging as a main issue of elderly welfare services policy. The study is based on the welfare panel data of 2016 (11th), and it is divided into the national selection group and the family selection group who are in charge of the elderly welfare services in terms of operation and delivery and financial burden. And analyzed the factors that affected the effect. As the result of the analysis, it is found that the higher the age of the elderly, the higher the age and education level, The more we experience welfare services, the more we receive public pensions, the greater the responsibility of the elderly, the greater the elderly spending. It is meaningful to provide basic data for solving the elderly supporting problem at the present time which is not sufficient for the elderly welfare system.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.503-503
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• 2022

미호천은 금강의 중권역에 위치하며 도심을 관통하는 전형적인 도심형 하천으로 금강대권역 물환경관리계획 내에서 다루는 지류하천 중 논산천과 함께 물환경 목표기준 미달성 하천으로 분류되어 중점관리 중권역으로 분류되어 있다. 금강 본류의 수질 악화에 큰 영향을 주는 하천으로 수질개선을 위해서는 목표기준 미달성 원인 파악 및 정책적 개선방안 모색을 통해 실질적인 정부와 지자체의 계획에 반영할 필요성이 있다. 그간 미호천 수질개선과 관련한 많은 연구가 진행되었으나, 연구의 대부분은 특정 오염원에 집중된 단기적인 조사에 편중되어 있다. 수질개선을 위한 정책분석 및 대응방안을 제시하기 위해서는 미호천 지류가 본류에 미치는 영향 등의 전반적인 하천 특성과 장기적인 이·화학적 수질 영향을 검토를 통한 정책적 지원 전략 수립이 필요한 상황이다. 본 연구에서는 미호천 수질개선을 목표로 수행되었던 환경기초조사업과 지자체별 정책사업들을 조사하고 수질개선 방안을 고찰함으로써 중권역의 수질개선을 위한 지역맞춤형 정책제언 및향후 지역 간 연계협력사업의 추진을 위한 참고자료를 제공하고자 하였다. 참고자료에는 수질현황조사 결과와 환경기초조사사업 및 미호천 관련 8개 지자체별 정책사업을 조사하였으며, 중권역 물환경관리계획에 수립된 예산 대비 현재까지 집행된 비율을 통해 이행도를 검토하였다. 마지막으로 미호천 수질관리 개선을 위한 축산오염원, 토지 비점오염원, 생활계 오염원, 산업계 오염원, 보 관리, 주민참여에 대한 부문별 개선방안을 제안하였다.

• Journal of agricultural medicine and community health
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• v.30 no.3
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• pp.279-292
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• 2005

Objectives: The purpose of this study is to analyze agricultural accident and disease using statistical data and materials about National Survey for Health & Nutrition in 2001 and to provide fundamental materials for studies about farmers' health and safety, decision of priority about research and policy. Results: Diagnosed chronic disease prevalence is 72.4% in farmer/fisher group, 49.8% in non farmer/fisher group. The chronic disease prevalence of musculoskeletal disease, circulatory disease, and gastroenteric disease is 46.5%, 18.2%, and 17.9% in farmer/fisher group respectively. The prevalence of musculoskeletal disease in farmer/fisher is 2.4 times higher than non farmer/fisher. This result shows that it need to evaluation for risk factors of musculoskeletal disease preferentially. Lifetime accident/poisoning rate is 18.2% In farmer/fisher group and 13.3% in non farmer/fisher group. The types of accidents were fracture>sprain>contusion and the reasons of accidents were traffic accident>falling/sliding. Conclusions: "Bad or very bad" response of farmer/fisher is almost 2 times higher than non farmer/fisher group. The rate of smoking and no exercising in farmer/fisher group is higher than non farmer/fisher group.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.1-6
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• 2006

This study was carried out to investigate yearly change in the precipitation component and the source strength to acid precipitation at Iksan area from 1997 to 2003. The average ratio of acid precipitation was 70.0% in 1997, 56.3% in 1998 and 36.4% in 2003. On the other hand, it ranged from 6.9 to 19.2% when precipitation was less from 1999 to 2002. The average annual wet depositions of major ionic component in precipitation were calculated by multiplying equivalent concentration by precipitation. The order of major anion component in precipitation was ${SO_4}^{2-}>Cl^->{NO_3}^-$. On the other hand, the concentration of cation component were ${Ca_2}^+>Na^+>{NH_4}^+>{Mg_2}^+>K^+$ in order. The negative correlation was shown between pH and ionic component in precipitation except for ${Ca_2}^+\;and\;Na^+$. The correlation coefficient between pH and ${SO_4}^{2-}$ was highly significant as -0.508, which suggests that ${SO_4}^{2-}$ played important role in increasing the acidity of precipitation. Also the anions such as ${SO_4}^{2-}\;and\;{NO_3}^-$ were highly significant with cations such as ${Ca_2}^+,\;{Mg_2}^+,\;K^+,\;{NH_4}^+\;and\;Na^+$. As a result though pH was enable to use the acidity index of precipitation in somewhere, evaluating only pH in precipitation was insufficient as the index to establish corresponding strategy for acid rain.