• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.551-563
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• 2012

Medical ultrasound systems have been used since 1950s, and are now widely used in most hospitals as indispensable diagnostic imaging systems. Since array probe was introduced in 1970s, beamforming technology using electronic signal processing has been adopted to the medical ultrasound system, and has been improved. Beamforming is a important technology which defines the resolution of the ultrasound system. In this paper, the technologies are introduced from basic beamforming principles to current trend. They include principles of beamforming using array probe, basic theory, and practical implementation, and recent topics of synthetic aperture imaging, adaptive beamforming, 2-dimensional beamforming using 2-dimensional array are also introduced. These various technologies will improve system performances continuously by merging innovatively with various technologies in other fields.

• The Journal of the Convergence on Culture Technology
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• v.4 no.4
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• pp.155-160
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• 2018

The article studies the effect of US real effective exchange rate and short-term interest rate on Chnise exports and imports using the EGARCH-GED model. This article analyze the effect of US major economic variables on China's exports and imports as the US pushes for interest rate hikes and worsens trade wars with China. The main results are as follows. The US short-term interest rate has a significant positive effect on China's trade volume. Even in the case of China's exports, US short-term interest rate has a significant positive effect. However, in the case of China's imports, in contrast to exports, US short-term interest rate do not have a significant effects and US real effective exchange rate has a significant positive effect. On the other hand, China's policy interest rate has a negative impact on China's imports and not statistically significant, but it has a significant positive effect on China's exports.

• Convergence Security Journal
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• v.18 no.5_2
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• pp.11-19
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• 2018

Because Korean military promotes employment support policy which give priority to the middle service officer who served more than 5 but less than 10 years and long term service officer who served more than 10 years, the support policy for obligated involuntary officer is relatively deficient. To make matters worse, national youth unemploy ment makes obligated involuntary officers suffer from serious unemployment crisis after discharge. These problems have bad effect on gaining ROTC KAOCS cadets who constitute about 80% of first appointment officers and because they are mostly discharged after just taking a short service, it's time to find a measure to solve the problem. Thus, this study is investigated to improve competitive rate of entry of ROTC KAOCS for securing outstanding manpower by deducing MR about legislation and system which are related to employment support for obligated involuntary officers and suggesting stable job secure plan for employment support, supplement system, and after discharge, model way of career management during military service of an obligated involuntary officers who are suitable for qualificated men who are needed for a company. Also, it will lead to combat power development of the military consequently.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.82-82
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• 2021

전 세계적으로 가뭄은 농업·식량안보·수자원관리·생태계 등 다양한 분야에서 부정적인 영향을 미치고 있다. 일반적으로 가뭄은 강수량의 부족으로 발생하고, 지표수와 지하수의 가용성이 제한됨에 따라 작물생산 및 사회·경제적으로 피해가 발생한다. 이러한 영향은 특정 가뭄 모니터링 및 조기 경보와 관련하여 가뭄 지표를 결정할 때 중요한 고려사항이다. 가뭄을 분석하기 위해서는 가뭄 지표를 적용하여 정확하게 반영하고 나타내는 것이 중요하다. 가뭄의 특성을 객관적으로 정량화하기 어렵기 때문에 다양한 지표와 계산을 통한 가뭄 모니터링 및 분석 기술이 필요하며, 강수량, 토양수분, 증발산량 및 식생과 관련하여 가뭄 지표가 개발되었다. 본 연구에서는 혼합 가뭄 지표 (Drought Indicator Blends) 활용하여 우리나라의 가뭄을 분석하였다. 혼합 가뭄 지표는 NOAA (National Oceanic and Atmospheric Administration)의 기후 예측 센터 (Climate Prediction Center, CPC)에서 여러 가뭄 지수를 단기 또는 장기로 구분하여 통합, 개발되었다. 단기 및 장기 혼합 제품은 PDSI (Palmer Drought Severity Index), Z-Index, SPI (Standardized Precipitation Index)를 결합하여 가뭄을 추정한다. 혼합 가뭄 지표는 해당 지역의 단기 및 장기 가뭄을 이해하는데 유용하게 활용할 수 있으며, 현재까지 미국에서 활발하게 연구가 진행되고 있다. 단기 지표는 비관개 농업, 토양수분 등 강수량에 밀접한 관련이 있는 가뭄과 관련되어 평가하며, 장기 지표의 경우 관개 농업, 지하수위 등 장기간 가뭄과 연관성을 가지고 있다. 단기 및 장기 혼합 가뭄 지표를 우리나라에 적용함으로써 기존 단일 가뭄 지수를 활용한 가뭄 분석 이상으로 다방면에서 효율적인 가뭄 모니터링을 할 수 있을 것이라 판단된다.

• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.97-108
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• 2019

In a situation where production of short-term income forestry products has been stagnant or decreased in recent years, the government or related agencies are trying to promote consumption of short-term income forest products. While consumer sentiment studies on short-term income forestry are being conducted as part of efforts to encourage consumption, most of the studies rely solely on a survey-based method. In the information age, consumer sentiment toward consumer goods is reflected mostly on social networking sites due to the spread of the Internet. It is necessary to avoid relying solely on a survey-based method in existing research and directly analyze social networking sites that reflect consumers' wishes. In response, this study identified consumer preferences for major short-term income forest products through social big data analyses and used the results to establish strategies for promoting the sale of short-term income forest products. This paper is different from previous research using only a survey-based method, and it uses SNS to understand consumer preferences. The results of this study are expected to directly help the government or related agencies promote consumption of short-term income forest products and, ultimately, help improve forest-related income and promote healthy forest condition.

• 대학교육
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• s.138
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• pp.18-21
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• 2005

해외 인턴십으로는 방학 중에 이루어지는 단기 인턴십과 학기 중에 이루어지는장기 인턴십으로 나누어진다. 해외 장기 인턴십의 경우, 주로 미국과 영국에서 이루어지고, 해외 단기 인턴십은 미국과 영국 이외에도 중국, 인도네시아 등지에서 이루어지고 있다. 해외 인턴십의 경우, 인도네시아를 제외하고는 모두 해외인턴십을 연결시키는 전문기관들의 도움을 받고 있다.

• Korean Journal of Plant Resources
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• v.9 no.2
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• pp.157-163
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• 1996

This study was carried out to control the decrease of yield and the deterioration of quality of Angelica gigas roots by bolting. This phenomenon resulted from lignificartion and dwarfishness of roots because of bolting formed for inflorescence and fruition. Seedlings were grown for 60,90 and 120 days in nursery of the green house, and transplanted in main field to compare with traditional seedling that grew for 1 year. Growth of the petiole length compare with length and leaf width of aerial parts in nursery showed a remarkably progress, and root characters as root length, root diameter and root weight grew more vigorously in the order of nursery periods. Bolting was not entirely formed in plots transplanted the seedlings which grown for short-time; 60, 90 and 120days, but showed the high bolting rate, 64.3%,in traditional seedling plots. Yield was higher in plots that transplanted short-time growing seedlings than that transplanted traditional seedlings, and among 3 kinds of nursery periods yields were high in the order of nursery periods. For the increase of yield and decrease of bolting rate, it was needed to transplant small seedlings of 3-4g/plant which grew in nursery for 90-120 days.

• The Journal of Korean Academy of Sensory Integration
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• v.14 no.1
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• pp.19-30
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• 2016

Objective : The purpose of this study was to identify the effects of Interactive Metronome (IM) training on short-term memory and attention for children with mental retardation. Methods : For this study, single-subject experimental research was conducted using an ABA design. We observed two children, twice a week for 9 weeks, which was 18 sessions in total. We evaluated the children's brain waves without intervention and the child's pseudo randomly selected sample of one short-term memory task as assessed in the baseline A phase for three sessions. In the intervention phase the children received 40-50 minutes of Interactive Metronome training twice a week, a total of 12 sessions. The short-term memory test and long form test as assessed after treatment, without brain wave in short form test measuring. During the baseline A phase, data were collected using the same procedure as the baseline A phase. Results : After the interactive metronome training, positive changes was observed in brain waves, attentions and short-term memory. Conclusion : The results of this study expect that IM training has a potential for improving cognitive functions of children with mental retardation. In addition, the results of this study can be used as basic data in attention and short-term memory of occupational therapy intervention for children with mental retardation.

• Journal of Korea Water Resources Association
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• v.46 no.7
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• pp.697-706
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• 2013

In recent, Korea has faced on water quality management problems in reservoir and river because of increasing water temperature and rainfall frequency caused by climate change. This study is effectively to manage water quality for establishment of algal bloom forecasting models with artificial neural network. Daecheong reservoir located in Geum river has suitable environment for algal bloom because it has lots of contaminants that are flowed by rainfall. By using back propagation algorithm of artificial neural networks (ANNs), a model has been built to forecast the algal bloom over short-term (1, 3, and 7 days). In the model, input factors considered the hydrologic and water quality factors in Daecheong reservoir were analyzed by cross correlation method. Through carrying out the analysis, input factors were selected for algal bloom forecasting model. As a result of this research, the short term algal bloom forecasting models showed minor errors in the prediction of the 1 day and the 3 days. Therefore, the models will be very useful and promising to control the water quality in various rivers.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.2
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• pp.73-85
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• 2016

Systematic and efficient forestry management is required because of the long-term low profitability of timber production and forest products. In this situation, non-timber forest products can be the solution to secure stable sources of income for workers in the forestry field. However, the existing studies for non-timber forest products focus on effective production and economic analysis and provide plans for increasing the income and improving the marketing system. Therefore, this research intends to analyze the spatial distribution as well as quantitative concentration of non-timber forest production. To achieve this goal, this study examined the regional concentration and dispersion of non-timber forest production in 2001, 2007, and 2014 using the coefficient of localization(CL) and location quotient(LQ) and investigated the change in spatial distribution using spatial statistics. The production of chestnuts generally showed a concentrated pattern in 2014 based on the outputs of the CL and LQ, but the result of spatial autocorrelation indicated a decrease in the spatial concentration. In addition, astringent persimmon showed more concentration from the output of CL than oak mushroom, but Moran's I suggests the opposite. Therefore, it is necessary to examine the spatial distribution to understand and improve the marketing system and intensify the production of forest products.