• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.2
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• pp.105-116
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• 2004

According to the developing advanced techniques and removal of Selective Availability, much research has been conducted to improve the accuracy of GPS positioning in absolute and relative mode by estimating the nuisance parameters such as atmospheric effect, clock errors and multipath. Especially, the continuous effort of establishing the CORS in many countries and the effort of ICS making effective global networking make more application areas and the necessity of more precise location is being increased. Some of the countries like German, Japan and Swiss already utilized the Virtual Reference System for better location accuracy and services. In this study, the VRS system is investigated in terms of system principle, required H/W and S/W, management and operation, revision of related law, expected application and market etc. and find optimal solution in each aspect for economic and fast set up of the system in this country. The analysis of Korean CORS, communication infra and market estimation is performed for the efficient system establishment. Also. the suggestion on the advertisement and education of the system is also included. It is expected that this study contributes for the establishment of effective and precise nationwide location service so that many SOC areas including navigation, GIS, Telematics, LBS can provides better service for the users.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.407-418
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• 2018

The frequency and risk of disasters are increasing due to environmental and social factors. In order to respond effectively to disasters that occur unexpectedly, it is very important to quickly obtain up-to-date information about target area. It is possible to intuitively judge the situation about the area through the image-map generated at high speed, so that it can cope with disaster quickly and effectively. In this study, we propose an image-map generation and visualization system from UAV images for real-time disaster monitoring. The proposed system consists of aerial segment and ground segment. In the aerial segment, the UAV system acquires the sensory data from digital camera and GPS/IMU sensor. Communication module transmits it to the ground server in real time. In the ground segment, the transmitted sensor data are processed to generate image-maps and the image-maps are visualized on the geo-portal. We conducted experiment to check the accuracy of the image-map using the system. Check points were obtained through ground survey in the data acquisition area. When calculating the difference between adjacent image maps, the relative accuracy was 1.58 m. We confirmed the absolute accuracy of the image map for the position measured from the individual image map. It is confirmed that the map is matched to the existing map with an absolute accuracy of 0.75 m. We confirmed the processing time of each step until the visualization of the image-map. When the image-map was generated with GSD 10 cm, it took 1.67 seconds to visualize. It is expected that the proposed system can be applied to real - time monitoring for disaster response.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.174-181
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• 1988

A comparison was made the differences of growth and some yield components of two soybean ecotypes (summer and two autumn types) at different planting dates (15 April, 15 May, and 15 June) and also made the different patterns of dry matter accumulation of one summer type and two autumn types of soybeans at Agricultural Experiment Farm, College of Agriculture, Dankook University, Cheonan City, in 1987. [Planting date experiment] Days to emergence of four varieties were observed no difference. and, therefore, it was speculated that field observation of the difference of cold tolerence between varieties was difficult. Shortening rate of flowering clays as planting dates delayed was no different between two ecotypes, summer vs. autumn types of soybean. Summer types, DN82029-3 and ES18085-1, were observed not greater difference of days to maturity between early and late planting dates as compared with that of autumn types, Changyeobkong and Paldalkong. At late planting, summer types were observed more to hasten days to ripening due to high temperature in late growing season than that of autumn types. This caused to decrease somewhat greater rate of some yield componments, and finally yield as planting date delayed. As compared to autumn types, summer types, DN82029-3 and ES18085-1 showed longer stem height and lower airdry weight at late planting. [Dry matter accumulation pattern] Stem elongation after flowering of three varieties, DN82029-3, Changyeobkong and Danyeobkong, ranged 17 to 32 cm and increment of leaf area index 0.83-1.53. DN82029-3 reached 49 days faster in maximum total dry weight than that of autumn types, Changyeobkong and Danyeobkong. However. maximum total dry weight of DN82029-3 showed 50% to autumn types. At 15 May planting, summer type, day-neutrality, transfered faster into reproductive growth phase without enough growth of vegetative growth and also hastened ripening days, and thus lower dry matter accumulation and finally lower yield.

• The Journal of Engineering Geology
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• v.26 no.2
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• pp.197-205
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• 2016

Rainfall-induced landslide disaster case histories are typically required to establish critical lines based on the decrease coefficient for judging the likelihood of slope collapse or failure; however, reliably setting critical lines is difficult because the number of nationwide disaster case histories is insufficient and not well distributed across the region. In this study, we propose a method for setting the critical area to judge the risk of slope collapse without disaster case history information. Past 10 years rainfall data based on decrease coefficient are plotted as points, and a reference line is established by connecting the outermost points. When realtime working rainfall cross the reference line, warning system is operating and this system can be utilized nationwide through setting of reference line for each AWS (Automatic Weather Station). Warnings were effectively predicted at 10 of the sites, and warnings could have been issued 30 min prior to the landslide movement at eight of the sites. These results indicate a reliability of about 67%. To more fully utilize this model, it is necessary to establish nationwide rainfall databases and conduct further studies to develop regional critical areas for landslide disaster prevention.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.59-64
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• 2000

We performed refraction, keratometry, slit lamp biomicroscopy. We selected 58 current spherical RGP lens wearers for this three-month study. All patients exhibits at least 0.75D of corneal astigmatism measured with the keratometer, and 37 patients had corneal astigmatism of 1.50D or greater. At least follow-up visit, we measured Snellen acuity with lenses, and performed overrefraction, overkeratometry and slit lamp biomicroscopy. We charted lens position, movement and surface quality. During the three month, biomicroscopy revealed no corneal edema and neovascularization on any patients. Fluorescein staining were 52 patients case of grade 0.5 patients case of grade 1, and 1 patient case of grade 2. In evaluating post-fit residual cylinder, on overrefraction as a percentage of refractive cylinder. By the initial visit, one-week visit, one-month visit, and two-month visit are 41%, 34%, 29%, respectively. In this data, we knew no change after one month. The average overrefraction for these eyes in absolute diopters is 0.26D(initial visit), 0.22D(one-week visit, 0.17D(one-month visit), and 0.16D(two-month visit). The use of a regimen containing a dedicated daily cleaner was more effective in maintaining patient comfort and lens cleanliness than was the use of a regimen containing only a multipurpose solution.

• Journal of the Korean GEO-environmental Society
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• v.10 no.1
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• pp.49-54
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• 2009

The seismic slope stability is most often evaluated by the pseudo-static limit analysis, in which the earthquake loading is simplified as static inertial loads acting in horizontal and/or vertical directions. The transient loading is represented by constant acceleration via the pseudostatic coefficients. The result of a pseudostatic analysis is governed by the selection of the value of the pseudostatic coefficient. However, selection of the value is very difficult and often done in an ad hoc manner without a sound physical reasoning. In addition, the maximum acceleration is commonly estimated from the design guideline, which cannot accurately estimate the dynamic response of a slope. There is a need to perform a 2D dynamic analysis to properly define the dynamic response characteristics. This paper develops a new hybrid pseudostatic method that links the modified one-dimensional seismic site response analysis and the pseudostatic algorithm. The modified site response analysis adjusts the density of the layers to simulate the change in mass and weight of the layers of the slope with depth. Multiple analyses were performed at various locations within the slope to estimate the change in seismic response of the slope. The calculated peak acceleration profiles with depth from the developed procedure were compared to those by the two-dimensional analyses. Comparisons show that the two methods result in remarkable match. The calculated profiles are used to perform pseudostatic analysis. The results show that use of peak or a fraction of acceleration at the surface can seriously underestimate or overestimate the factor of safety, and that the proposed procedure significantly enhances the reliability of a standard procedure.

• The Journal of Fisheries Business Administration
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• v.30 no.2
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• pp.91-105
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• 1999

본 연구는 필자가 미국 Oregon 주의 수산업사를 조사하던 중 1940년대부터 시작된 미국으로 이민 한 중국인들이 미국 서부 수산업에 미친 영향이 거대하다는 것을 발견하고, 이에 관련된 문헌을 찾아 최초 미국 서부(특히, California 주)에 이민하기 시작했던 중국 이민자들이 미국에서 수산업 활동을 시작한 배경과 그에 따른 영향 등을 살펴본 것이다. 중국인이 미국에 이민하기 시작한 배경은 두 가지가 있다. 하나는 국내적인 요인으로서 중국에서의 경제적 빈곤과 정치적 핍박이었고, 다른 하나는 국외적인 요인으로서 금캐기가 가능하다는 소식 등 미국 생활에 대한 동경이었다. 중국인의 미국 이민사에서 독특한 점의 하나는 중국 남부지 방에 위치한 광동성 지방민들이 절대적인 비중(90% 이상)을 차지하고 있다는 것이다. 가장 큰 이유는 광동성은 일찌기 외국문물이 드나드는 곳이어서 인근 광동성 지방민들은 다른 지방민보다 외국소식을 쉽게 접할 수 있었기 때 문이었다. 미국에 도착한 광동성 지방민들은 쉽게 직업을 구할수 없는 처지이 되자 그들이 익숙하게 알고 있는 바다생활에 뛰어들었고, 마침내는 미국 서부에서 진취적인 어업인이 되었다. 따라서 서부에서 최초의 상업적 어업인이 되었으며, 미국 서부에서 시작한 중국인의 수산업은 점차 다른 주로 퍼져 나갔다는 기록은 중국인이 미국 전역에서 최초의 상업적 어업인이었음을 알게 한다. 최초의 중국인 어촌은 1854년 San Francisco의 Rincon Point에 세워졌으며, 25척의 어선과 150여명의 주민이 살았다. 그들이 사용한 어구ㆍ어업은 통발, 정치망, 선망, 낚시, 연승 등이었으며, 중국풍의 어선과 어구를 직접 만들어 새우, 철갑상어, 대구, 우럭, 넙치, 게, 가재, 전복 등을 어획했다. 1888년에는 San Francisco 전역에 20개의 어촌이 형성되었고, 2천여명의 어업종사자가 있었다. 1900년부터는 점차 그 수가 줄기 시작하였다. 가장 크고 오래 지속된 어업은 새우어업은 1860년대부터 1940년 중반까지 계속되었으며, 이 어업에 의해 새우가 인근 지역의 보편적인 식품으로 자리하게 되었다. 인디언에 의해 단순한 장식품으로 사용되던 전복은 중국인에 의해 그 맛이 알려지게 되었고, 유럽이나 미국 동부로 팔려 나갔다. 상어 또한 중국인에 의해 먹기 시작하였으며, 내장에서 뺀 기름이 사용되기 시작하였다. 게를 잡기 위한 통발과 시장형성으로 San Francisco부두의 많은 부분이 차지되었다. 1880년대부터 시작된 해조류의 채취는 처음에는 인디언들에 의해 시작되었으나, 곧 중국인들에 의해 본격화되었다. 광동성 지방민들의 초속식품의 하나인 오징어를 잡기 위해 중국인들은 배를 만들어 야간에 횃불을 밝혔다. 오징어는 곧 San Francisco 주민은 물론 태평양 연안주와 미국 전역에 있는 중국식당에서 수요가 지속되었다. 중국인들은 1849년부터 연어를 상업적으로 잡기 시작하였으며, Washington주에서 시작되어 Oregon, British Columbia, Alaska로 퍼진 통조림 공장은 주로 중국인의 노동력에 의해 운영되었다. 위와 같이 중국인들이 미국 수산업 분야에서 크게 활동하자 미국인들은 그들의 수산업 활동을 제재 또는 통제하고자 일정한 납세를 명시한 각종 법률, 특히 The Chinese Exclusion Act 등을 제정하였다. 미국 서부에서 중국인의 수산업은 미국인의 법적 제재, 중국인의 다른 직업으로의 이직 등으로 1940년대를 끝으로 막을 내렸다.

• Korean Journal of Environment and Ecology
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• v.15 no.3
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• pp.213-223
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• 2001

This study was carried out to clarify the distribution pattern of Salicaceae species which are considered as obligatory riparian vegetation, and also the correspondence between their distribution and the environment factors. Eighty-three study sites by stratified sampling were selected from the upstream to the downstream of An-sung stream. Vegetation factors such as coverage by species, disturbance, etc., and environmental factors including microtopography, soil properties, etc., measured and analyzed. Salicaceae species were identified as total 2 genera, 11 species through all study area, and the average occurring species were 2.8 species.5. koreensis among other species showed highest occurring frequency at An-sung streams, and also it was distributed widely through study area. S. gracizistyla was mainly fecund at upstream sites, where sandy soil texture and high longitudinal slope were developed. S. purpurea vats. japonica was mostly observed in the sandy soil, the same as S. gracilistytu and however, was not dominant but rather mixed with S. gracitistyta and S. koreensis. On the other hand, distribution of S. glandulosa were closely related with littoral zone of the lake and the lower sea level with sandy loam and loamy sand Boils of high organic matter content. Under CCA, canonical correspondence analysis, distribution of Saticaceae species was positively correlated with environmental gradients such as soil properties along to topography.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.123-129
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• 2017

This paper proposes a new nonnegative matrix factorization (NMF) based direction-of-arrival (DOA) estimation method for multiple sound sources using a dual microphone array. First of all, sound signals coming from the dual microphone array are segmented into consecutive analysis frames, and a steered-response power phase transform (SRP-PHAT) beamformer is applied to each frame so that stereo signals of each frame are represented in a time-direction domain. The time-direction outputs of SRP-PHAT are stored for a pre-defined number of frames, which is referred to as a time-direction block. Next, In order to estimate DOAs robust to noise, each time-direction block is normalized along the time by using a block subtraction technique. After that, an unsupervised NMF method is applied to the normalized time-direction block in order to cluster the directions of each sound source in a multiple sound source environments. In particular, the activation and basis matrices are used to estimate the number of sound sources and their DOAs, respectively. The DOA estimation performance of the proposed method is evaluated by measuring a mean absolute error (MAE) and the standard deviation of errors between the oracle and estimated DOAs under a three source condition, where the sources are located in [$-35{\circ}$, 5m], [$12{\circ}$, 4m], and [$38{\circ}$, 4.m] from the dual microphone array. It is shown from the experiment that the proposed method could relatively reduce MAE by 56.83%, compared to a conventional SRP-PHAT based DOA estimation method.

• Sijohaknonchong
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• v.19 no.1
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• pp.207-234
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• 2003

The purpose of this research paper is to study the characteristics of Huang Yunseok's sijo and it's implications for his poetic intentions. Huang Yunseok's sijo is didactic in its presentation of facts and ethical lessons. The two main facts it presents are royal favors and his clan's pride. Royal favors concern. for example, encouragement of the king, the king's birthday and deathday, and securing a government position by the king's order. His clan's pride concerns, for example, the geographically wonderful place of Huang Yunseok's ancestor's tomb, his ancestor's great conduct, his clan's beautiful tradition, his birth place, and his birth dream. The main content of the ethical lessons concerns cultivation of the human mind and practicing Confucian ethics. Examples of the former describe the purpose of Confucian study, the ethical doctrine that human being's inborn nature is good, the character of the human mind, and the method of cultivating the human mind. Examples of the latter describe the moral rules to govern the Five Human Relations, separation between husband and wife, and discrimination between males and females. The poetic intention of Huang Yunseok's sip consists of political and economic self-promotion and theoretical devotion to Confucian ideology. Proud of his educated, high Confucian clan, he tries to get self-promotion politically and economically by vowing loyalty to the king. He implies devotion to the Confucian ideology through his description of the practice of the Confucian moral rules, the clinging to traditional Neo-Confucianism, and his insistence on the Neo-Confucian theory that all human beings and animals are the same in their original nature. In conclusion, the didactic character of Huang Yunseok's sip stems from his intention to promote himself politically and economically and his theoretical devotion to Confucian ideology. The way of indicative expression originates from the didactic character of Huang Yunseok's sijo.