• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.2
• /
• pp.213-217
• /
• 2015

Microwave Photonic(MWP) filters capable of use a bandpass filter or a notch filter with large bandwidth have been proposed. 4-lines${\times}$2-bit fiber-optic delay lines with a unit time-delay difference of 50 ps were experimentally realized. By changing the time-delay difference and the coefficients of microwave-modulated optical signals, the bandpass and notch filters were implemented and characterized.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.354-361
• /
• 2009

최근 물 사용 및 배분과 관련하여 각종 갈등이 첨예화 되면서 수리권에 대한 체계적인 정리가 필요하게 되었다. 특히, 각종 수리권의 적용 범위나 한계를 논하기 위해서는 근본적으로 하천의 자연유량과 인공유량에 대한 이해가 우선되어야 하는데 이는 수리권의 본질을 이해하는데 기본적인 사항이다. 이를 통해 자연스럽게 '강변수리권'과 '지역수리권', 그리고 또 다른 대표적인 수리권인 '점용수리권'에 대한 비교 검토를 함으로써 수리권에 대한 올바른 인식을 가능하게 하며 이로 인해 물의 합리적이고 효율적 배분에 기여할 수 있다. '강변수리권'은 오로지 강변에 위치한 토지에 필요한 물에 대해서만 적용되는 수리권으로 결과적으로 농업용수에 대한 권리이며 지방자치단체가 아닌 강변 토지 소유자에게 부속되어 있고 하천의 자연유량에만 적용되어 댐 건설로 인해 추가적으로 발생하는 유량에 대해서는 적용하지 않는다. 또한, '강변수리권'은 비록 사용하지 않아도 소멸되지 않으나 한번 소멸되면 회복할 수 없으며 타인에게 양도할 수 없다. 아울러 '강변수리권'끼리는 똑같은 우선권이 있기 때문에 물이 부족한 시기에는 주어진 양을 공유해서 사용하여야 하며 소량이지만 생활용수로 사용코자 하는 경우에는 등록증서가 필요하며 물을 저장해서 다른 시기에 쓰고자 한다면 수리권 허가가 필요하다. '점용수리권'은 "특정 기간동안 특정장소에서 특정한 용도로 특정 수원(水源)으로부터 특정한 양을 취수하는 배타적 권리이다". '점용수리권'은 물의 가용성(availability)을 기초로 하고 있으며 합리적이고 유용한 용도에 사용하는 것을 일반적인 원칙으로 하고 있다. '점용수리권'은 '선점수리권(first in time, first in right)'이라고도 하는데 '강변수리권'과는 다르게 강변에 인접하지 못한 토지소유자가 물을 취수하여 물을 이동시킬 수 있는 권리로 허가없이 증량할 수 없으며 5년간 사용하지 않는 경우에는 소멸된다. '점용수리권'을 얻고자 하는 사람은 장기간 물을 저장하여 사용하고자 하는 '강변수리권자'나 강변에 인접하지 않은 토지에서 지표수나 지하수를 저장하거나 사용하고자 하는 사람들이다. '지역수리권'을 뒷받침하는 사례로 자주 이용되는 미국의 경우에 주(州) 헌법이나 주(州) 수법에 주(州)내의 모든 물은 주(州)의 주민에 속한다고 천명하고 있다. 그러나, 추가적으로 수질관리, 홍수관리, 댐 운영, 재해방지 등 물과 관련한 포괄적인 기능도 주(州)의 책임으로 명시하고 있어 지방정부주(州)가 단지 물의 사용에 대한 권리만 위임받은 것이 아니며 물 관리에 따른 모든 책임까지도 함께 담당하고 있다는 우리나라와 같이 지방자치단체의 물 이용에 대한 권리만 의미하는 '지역수리권'과는 근본적으로 다름을 알 수 있다.

• Korean Journal of Environment and Ecology
• /
• v.17 no.1
• /
• pp.56-70
• /
• 2003

Reviewing the trend of land use in urban cultivated land, the large part of land has been changed into the high-profit cultivated land of green houses or the developing areas. So, its percent of cultivated land in land use comparing to the other types of cultivated land would get far higher. Therefore, this study aims to identify the characteristics of landscape ecological pattern in the cultivated land of green houses and to find its alternatives for management, which would be a basis of regional planning and management in terms of space and time. The cultivated land of green houses, whose its area reaches 19.3ha, in Seoul are mainly dispersed on the south eastern part of Seoul and its area is larger than the other types of cultivated lands. According to the result of shape index analysis, its perimeters were very simple. Also, Analyzing the first three major neighboring land use to the cultivated land of green houses, the most frequent biotope types of neighboring land use to the cultivated land of green houses were that transportation facility represented 60%, forest, 43%, the other types of cultivated land, 36%, and residential area, 33%. The cause why the percent of transportation facility was higher in the neigh-boring land use types was assumed for the production and distribution of crops. On the basis of the result of landscape ecological pattern analysis, the cultivated land would be managed and contributed to enhance biodiversity and urban environment preservation.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.6 no.10
• /
• pp.603-612
• /
• 2016

This study will observe the following subjects based on the railroad: First, the development of St. Pancreas Station, which is the gateway to London from other Europe continent, and King's Cross Station, which connects all the intercity within London. Second, the planning characteristic of urban regeneration case which was driven from Camden district, the center of King's Cross Central, which is located in between the two stations, St. Pancreas and King's Cross. Third, based on the the two stations and urban regeneration, this study attempts to investigate the direction of urban regenerating plan and its detailed strategy. As a result, King's Cross Station, St. Pancreas Station and the King's Cross Central area, which is an adjacent area from the two stations, were a slum for a long time. However, the two close stations played a role as the United Kindom and London's railroad network by sharing the common denominator of having the international high-speed railway among the Europe continent and being the connection of National railroads within London. Eventually, based on such potential of railroad traffic, King's Cross Central area was newly regenerated. The consequence of this study has shown that not only the physical modernization of buildings, implementation of compact railroad network supporting both ground and underground of each area or traffic connection was organized in London, but also secured the pedestrian way for easier transfer and planned and allocated facilities by considering citizen's publicness and multilateral use.

• The Korean Journal of Quaternary Research
• /
• v.25 no.1
• /
• pp.31-39
• /
• 2011

Phytolith of soil in earthenware buried in the wooden chamber tombs at the archaeological site in Hwangseong-dong, Gyeongju along Hyeongsan River are analyzed. The study area has adjoined the seat of government during approximately thousand years in Shilla Dynasty and can be regarded as being closely related to the agricultural activities using the floodplains of Hyeongsan River. By the analytical results, Phragmites, Paniceae and Andropogoneae as well as Oryza sativa are found in the lower horizons, indicating the agricultural activities in the nearby areas. It is suggested for understanding the use of earthenware that the comparisons of buried soils in the site and soils in the earthenware and analysis on the macro plant fossils of soil in the earthenware are needed.

• Proceedings of the KSEE Conference
• /
• 2008.10a
• /
• pp.17-28
• /
• 2008

국책사업이나 SOC의 확충을 위한 도로 및 철도의 건설에서 적용되는 터널의 단면크기를 보면, $50m^2$에서부터 $100m^2$이상의 중 대단면 터널이 주를 이루고 있으나, 전력구, 통신구, 소규모로 운영되는 광산의 채광용 터널, 용수를 위한 도수로터널 등 특수한 용도로 설계, 시공되고 있는 터널에서는 $20m^2$이하의 단면크기를 갖는 경우가 있다. 이러한 소단면 터널의 경우에는 협소한 작업공간으로 인하여 적용공법 뿐만 아니라 장비의 사용 또한 제약을 받게 되어 작업효율이 저하되고 공사기간이 늘어나게 되는 등 여러 가지 문제점을 안고 있다. 특히, 에멀젼 폭약을 사용하는 발파에서 먼저 기폭된 발파공의 충격압력에 의해 인접공의 폭약이 예비압축(Precompression)되어 사압현상을 일으키고 잔류약을 발생시키는 사례가 종종 발생하고 있다. 사압현상은 당해 발파의 실패와 함께 2차적인 사고의 위험요인이 될 수 있으므로 이를 방지하기 위한 대책을 수립하여야 한다. 이를 위해 기존 문헌을 통하여 사압현상의 원인과 발생 가능성을 검토하였고, 국내에서 주로 사용되는 에멀전폭약의 수중 내충격성시험과 충격압력 전달시험을 실시하여 사압현상의 발생정도를 측정하였으며, 사압현상이 발생한 소단면 터널현장을 대상으로 대책을 수립하여 적용하였다. 심발방법을 변경하여 전단의 충격압력을 견딜 수 있는 공간격을 확보하고 뇌관의 초시간격을 적절하게 배치한 발파패턴을 적용한결과, 사압현상을 억제하고 잔류약의 발생을 감소시켜 계획 굴진장을 확보하고 파쇄석의 크기를 감소시키는 등 양호한 결과를 얻을 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.573-575
• /
• 2015

Positioning system using satellite GPS is used at positioning, navigation, acquisition time information and other various field and taking an important part precision guided weapon such as missile. But commercial code(C/A code) do not have ECCM. Therefore commercial code is vulnerable to various jamming techniques and noise jamming from near station can attack even the encrypted military code(P code) GPS. In this paper, GPS jamming techniques, North Korean GPS jamming cases and anti-jamming GP S technologies are surveyed and described.

• Korean Journal of Plant Taxonomy
• /
• v.50 no.2
• /
• pp.166-198
• /
• 2020

The flora of vascular plants in the Gibaeksan Mt. County Park and its neighboring mountains, located at the boundary between Geochang-gun and Hamyang-gun in Gyeongsangnam-do province in Korea, were surveyed for a total 46 times from April to September of 2011, in July of 2012, and from April of 2015 to August of 2018. The result of this survey revealed 659 taxa composed of 107 families, 346 genera, 583 species, 14 subspecies, 46 varieties and 6 forms. Among them, 25 taxa were endemic plants to Korea, and 18 taxa were rare and endangered plants of Korea. The floristic regional indicator plants including cultivated plants were 5 taxa of grade V, 5 taxa of grade IV, 29 taxa of grade III, 30 taxa of grade II and 38 taxa of grade I. Forty-three taxa of alien plants were found in this area. In addition, 500 taxa out of a total of 649 taxa were categorized by usage into eight groups, including among others an edible group containing 257 taxa, a medicinal group containing 206, a pasturing group containing 220, and an ornamental group containing 84, with some taxa belonging to more than one group. The flora of this surveyed area belongs to the southern province among the floral provinces of the Korean Peninsula.

• Journal of the Korea Society for Simulation
• /
• v.15 no.3
• /
• pp.23-30
• /
• 2006

A recommender system for E-commerce site receives information from customers about which products they are interested in, and recommends products that are likely to fit their needs. In this paper, we investigate several methods for large-scale product purchase data for the purpose of producing useful recommendations to customers. We apply the traditional data mining techniques of cluster analysis and collaborative filtering(CF), and CF with reduction of product-dimensionality by use of latent semantic indexing(LSI). If reduced product-dimensionality obtained from LSI shows a similar latent trend of customers for buying products to that based on original customer-product purchase data, we expect less computational effort for obtaining the nearest-neighbor for target customer may improve the efficiency of recommendation performance. From simulation experiments on synthetic customer-product purchase data, CF-based method with reduction of product-dimensionality presents a better performance than the traditional CF methods with respect to the recall, precision and F1 measure. In general, the recommendation quality increases as the size of the neighborhood increases. However, our simulation results shows that, after a certain point, the improvement gain diminish. Also we find, as a number of products of recommendation increases, the precision becomes worse, but the improvement gain of recall is relatively small after a certain point. We consider these informations may be useful in applying recommender system.

• Journal of Soil and Groundwater Environment
• /
• v.11 no.1
• /
• pp.54-64
• /
• 2006

Chromated copper arsenate (CCA), a wood preservative, has been widely used to protect wood products from attacks by bacteria, fungi and insects. However, the use of CCA is currently forbidden or limited to some applications in many countries because the toxic elements (Cr, Cu, and As) of CCA are released into the environments during outdoor uses, which may cause adverse health effects on humans and ecological systems. This study was conducted to investigate the distributions of chromium, copper and arsenic in soils adjacent to two CCA-treated wood structures. In a 7 month old pond entry structure, ten surface soil samples (0-2.5 cm) were collected at lateral distances of 0, 0.5, and 1 m from the stairway, and nine surface soil samples were collected beneath the deck. Nine top soil samples were taken from a 2 year old sound barrier structure at lateral distances of 0, 1, and 2 m. Background surface soil samples were also collected from each structure. Samples were analyzed for some physicochemical properties such as pH, electrical conductivity, organic matter content, and soil texture. Following the extraction of the elements with a microwave digestion system, samples were analyzed for Cr, Cu, and As. The concentrations of the three elements in soils adjacent to the structures were significantly elevated compared to the background levels, indicating that the elements have been leached out of the structures. Released e1ements showed lateral concentration gradients within 1 m. The elevations of the three elements in soils underneath the deck did not seem different (background-corrected concentrations: Cr, 5.01 mg/kg; Cu, 5.50 mg/kg; As, 4.91 mg/kg), while the elements in soils near the sound barrier were elevated in the order of As>Cu>Cr with measured concentrations of 49.7, 44.7 and 52.5 mg/kg, respectively. Background As, Cu, and Cr concentrations near the sound barrier were 9.88, 30.8, and 46.5 mg/kg, respectively. These results showed that CCA constituents are released into the environment and it is suggested that risk assessment need to be conducted to investigate harmful effects of the released elements on humans and ecological systems.