• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.995-1002
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• 2022

Global Navigation Satellite System(GNSS) is a convenient system that acquires position and time information of a receiver if only satellite signals can be received anywhere in the world. However navigation signals include errors and a position error occurs according to the reception state of the signal. Also, a position error is affected by the geometric arrangement of the satellites. Therefore a receiver position performance varies by the number and status of visible satellites The condition of satellite signals is not good when the satellite rises or sets and the position change of receiver occurs when the signal is blocked by an obstacle such as a building in the urban area. In this paper, we proposed methods to improve the GNSS performance by using pseudorange correction method estimating the correction amount and the visible satellites selection method. By applying the proposed methods to an environment in which the number of visible satellites changes variously, the performance enhancement was verified.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.521-530
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• 2009

This study has been made to execute a research in order to lead the improvement of indoor air quality, examining the indoor ventilation characteristics by using a numerical analysis method. To this end an extensive parametric investigation are made according to various external flow variables such as main wind direction and wind speed by season, building layout design, and location of ventilators, etc. in Daedeok Techno Valley, one of large-scaled apartment in Daejeon. It is observed there was a significant difference of main wind direction between summer and winter. The main wind direction in summer was a south wind, and on the contrary the direction in winter is northnorthwest, which is similar to the average main wind direction for 10 years. One of the important calculation results is that the change of wind direction causes a significant effect on the apartment ventilation by the change of pressure difference around each complex of apartment. In case of favorable area of ventilation, the indoor ventilation rate can meet 0.7 ACH from the standard value only with natural ventilation. On the contrary, in other area the value was much lower than the standard value. If the calculation result applies to the design of layout apartment or placement of ventilators, it will be greatly helpful to the energy saving because it can be parallel with the natural ventilation to help securing ventilation rate, not much depending on the mechanical ventilation.

• Journal of the Korean Institute of Educational Facilities
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• v.4 no.1
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• pp.53-64
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• 1997

지난 20여년간의 비약적 경제 성장을 통하여 우리 사회는 모든 물리적 측면에서 양적인 성장과 질적인 발전을 거듭하여 왔다. 이러한 경제 성장기를 거치면서 우리의 삶은 다각도에서 변화를 겪었으며 건축환경에도 많은 변화가 있었다. 정보화, 세계화라는 시대적 흐름은 우리의 생활자체를 급속도로 변화시키고 있으며 업무용 시설을 포함한 모든 건축물이 대형화, 고층화 뿐 아니라 정보화, 현대화되고 있다. 그러나, 교육의 중요성과 이를 뒷받침해 줄 학교 시설의 중요성에도 불구하고 교육환경의 질적 개선은 상대적으로 낙후되어 있는 상황이라고 할 수 있다. 교육개혁위원회의 교육개혁방안이 계속적으로 나오고 있고 서울의 불암초등학교를 필두로 한 시설 현대화 시범학교가 시도별로 마련되고는 있지만 전반적인 교육 환경은 아직 열악한 상태이다. 특히 구도심부에 위치한 초등학교의 경우, 준공된 후 30년 이상 경과된 학교 건물을 사용하고 있는 경우가 적지 않아 안전상의 문제마저 안고 있는 실정이다. 따라서, 건물의 내구 연한이 그 한계에 달해 가고 유지보수비용이 계속적으로 늘어 경제성을 잃어 가고 있는 학교들을 대상으로 한 재건축과제가 신설 학교의 신축 또는 기존학교의 이전 못지 않은 주요 과제로 대두되고 있다. 더욱이 기존 학교의 재건축사업은 수업을 진행시켜가며 철거 및 신축공사가 단계적으로 수행돼야 한다는 어려움을 갖고 있다. 본 연구는 초등학교의 재건축을 위한 기본적인 자료를 정리하고 배치 및 평면 계획을 중심으로 한 계획 대안을 작성, 검토하여 대안별 장단점을 분석한 후 가장 바람직하다고 평가되는 안을 제시하는 것을 연구의 범위로 하였다. 계획안의 작성에 앞서 실시된 문헌조사 및 실측조사를 통하여, 신축되는 홍파초등학교에 필요한 시설의 내용 및 규모가 산정되었는데 특기할 사항은 좁은 대지임에도 불구하고 가능한 체육관 시설을 포함시키고자 하였다는 것이다. 홍파초등학교 부지는 $8,960m^2$ 정도밖에 안되는 좁은 부지로서 운동장도 제대로 확보할 수 없는 상황이었으나 체육관의 높은 활용도 및 장래의 필요성을 고려하여 소규모라도 계획되는 것이 바람직하다고 판단하였다. 열린교육에의 대응, 제반 특별교실의 확충, 식당 및 지하주차장의 확보 등 모든 시설이 현재 및 장차의 사용에 적합하도록 계획하여 현 시설의 1.5배 정도의 연면적을 갖는 신축 계획안을 작성하였다. 서울대학교와 광운대학교에서 분담하여 실시된 계획안의 작성을 통하여 총 4개의 계획안이 도출되었으며 이 대안들을 채광 및 환기, 학년별 zoning, 기능별 zoning, 열린교실의 정도, 지역사회에의 개방성, 재건축 공사의 용이성, 규모, 옥외공간의 활용성, 동선 계획, 조형성 등 10개 항목을 기준으로 평가하였다. 이러한 비교분석을 통하여 결론적으로 제1안을 최적안으로 제시하게 되었으며, 이를 바탕으로 구체적인 최종 설계안이 도출되기를 기대하는 바이다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.339-346
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• 1999

This experiment was carried out to determine harvest date and cultivar effects on the agronomic characteristics, forage yield, and quality of fall sown oat (Avena sativa L.) at the forage experimental field, College of Agriculture and Life Sciences, Seoul National University, Suweon from August to November 1993. The experiment was arranged in a split plot design with three replications. The main plots were consisted of the harvesting dates, suchas early (11 October), mid(21 October), and late(1 November), the subplots were consisted of different maturities of oat cultivars, such as 'West', 'Cayuse' and 'Magnum'. The first heading date of an early maturing culivar, West, was observed on 10 October, and the heading increased up to 30% at the late harvesting date. The average dry matter (DM) content of oat cultivars increased significantly from 12.8 to 15.9% as the growing stage progressed(p<0.01). The average dry matter percentage of West, Cayuse, and Magnum was 15.4, 13.4, and 13.5%, respectively. The crude protein (CP) content of oat cultivars decreased significantly from 20.1 to 13.3% as the harvesting date was delayed(p<0.01), and the CP contents of midseason and late maturing cultivars, Cayuse and Magnum, respectively, were significantly higher than that of an early maturing cultivar West (p<0.01). The mid harvesting date showed the highest acid detergent fiber(ADF) and neutral detergent fiber (NDF) contents than the other harvesting dates, and an early maturing cultivar West had higher ADF and NDF contents than the midseason and late maturing cultivars, Cayuse and Magnum, respectively. The in vitro dry matter digestibility(IVDMD) of oat cultivar West decreased as the harvesting date was delayed, but that of Cayuse and Magnum decreased only by the mid harvesting date. Cayuse and Magnum showed 3~4% higher digestibility than West. The correlation coefficient between IVDMD and ADF content was -0.86. The average dry matter yield of oat cultivars increased from 2,901 to 5,901kg/ha as the harvesting date was delayed(p<0.01), but no significant difference was found among oat cultivars. The corrdelation coefficient between DM yield and gorwing degree days(GDD) was +0.86. The results of this study indicate that a delay in harvesting date would be recommendable for the increase of dry matter yield when fall-sown oat is grown. Especially, the DM yield of the midseason and late maturing cultivars, Cayuse and Magnum, respectively, can be increased without much change of forage quality although the harvesting date are delayed.

• Fire Science and Engineering
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• v.27 no.1
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• pp.52-59
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• 2013

In this study, tests were conducted to establish a fire engine of relay waterproof and utilization in order to maintain the pressure in a situation that require high-pressure water-resistant such as a high-rise building fire, etc. As a result of test on the change of a relay waterproof pressure, the measurement result with the hydrant intake of a fire engine opened has reduced approximately 20 % compared to the measurement result with the hydrant intake closed. Similar efficiency showed in the test result that change the pressure of 2 fire engines respectively to use them more efficiently at a fire fighting activity site. A fire engine operation and utilization is proposed based on this study result in order to cope effectively with a fire site requiring high-pressure stream in a high-rise building fire, etc. by using a fire engine held at present because there is no fire pump with high-pressure stream ability arranged at the fire station and there is no regulation on high-pressure fire-fighting pumps in a type approval and verification technology criterion for a fire engine.

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.179-189
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• 2012

The aim of this paper is to research the change in the turbulent flow and the AOA(Angle Of Attack) occurred by $40^{\circ}$ crosswind to the direction of runway through the three-dimensional numerical analysis and to predict the take-off and landing flight stability. As a result, the maximum amplitude of AOA variation on runway reached $2^{\circ}$ within 3 second because of the wake formed by the constructions in the vicinity of the airport, and the overall effects appeared as an irregular aperiodic forms. Additionally, it was observed that the layout and shape of the buildings effected on the strength of turbulence directly, and the rapid flow generated between the buildings changed into stronger wake and eventually expected that the flow raises serious take-off and landing flight instability.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.100-121
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• 2009

This study is subjected to those gardens of the Korean Folk Village 'Oeam-Ri' designed in 1920s. - transitional period of traditional gardens - and define socio-cultural change's influences and through documents on garden design, descendant's testimony and measured drawings, to understand that period's garden culture's characteristics according to garden design elements. This study applied following analysis methods and procedures to derive out characteristics of transitional garden culture. Analysis on socio-cultural characteristics in 1920s. Analysis on actual condition of transitional garden's design. In this point Outline of the Garden, Space formation, Garden designing elements are (1) water landscape, (2) plant, (3) structures, (4) paving, to derive out characteristics of the transitional garden. The results follow as below; First, during the transitional period 1920s, the economical development, fueled by opening nation's door to foreign countries and indication of collapse of statue systems together with idea of practical science and Enlightenment Thought, was element of changes in garden style. Second, Garden Designers of transitional gardens in 'Oeam-Ri' were limited to upper class of the society. They were wealthy enough to maintain their high social statue in rapidly changing society. As results, tendency of returning to nature developed gardens located in a site of scenic beauty and development of geographical features arranging techniques, and also showed copying foreign styles. Third, arrangement of garden and space composition, in most cases, composed of buildings and yards. Changes in water landscape features and garden spaces are centered to main-yard. Major changes of the garden spaces are water landscapes and plants that showing foreign influences. Fifth, scenic appearance techniques appears with dense garden space and emphasizing visual scenic view. Sixth, the characteristics of transitional garden design techniques are development of geographical feature arranging techniques, changes and mixture of the materials and garden types, emphasizing garden's decorative beauty, change of concept of yard within house into garden, changes from 'borrowing of landscapes' to 'selecting landscapes', changes of front garden from emptiness to fullness, changes of attitudes of enjoying gardens from 'staying calm in the garden' to 'moving or walking in the garden', changes to inner-oriented view, and changes from 'just watching and enjoying the nature' to 'enjoying specific objects'. This study is one of the efforts to restore the identity of Korean Traditional Garden by approaching and observing modern era which function as bridge between tradition and present day, and we observed transitional aspects of changes of traditional garden into modern garden. Hereafter, more studies will be needed to Modern Garden Design be recognized as part of Korean Garden Design History and these would be author's next assignment.

• Archives of design research
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• v.12 no.4
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• pp.231-241
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• 1999

This study propose to analyze the design method and the form elements of museums, of works by Richard Meier, and through the analysis, spacial characteristics of museums will be understood. The museum works of Richard Meier, as an exhibition space, not only display the art works efficiently, but they also offer visitors the opportunity to experience the art of architecture, as a cultural space. Richard Meier, when working on the projects, has utilized the design methods and the architectural language, learned from Mies van der Rohe and Le Corbusier, resourcefully. Having the structural grid as basis, the rational rectangular forms were intended for exhibition space, while the circular and partial circular forms of geometry were utilized in formative space. This was able to maintain the balance between functional and formative space. In the museums of his works, the ramp and the glass wall separated from the structure become very important means of expression. The ramps, not only make people to enjoy the interior and exterior of museum, but also able them to see the works of art from different distances and angles repeatedly and the large glass wall reveals the various shapes of interior to exterior. In comparing with the design method and language of two masters mentioned, the design principles and elements, developed by Meier were applied to the site plans, exhibition space planning and elevations to manifest its originality. The design concept, derived from the urban fabric and historical buildings around, gave harmony to the museum with its surroundings, and employing the deformed axis brought variation and the effect of diversion to the site plan. The exhibition space is much vitalized by the well arrangement of various exhibition fixtures in the museum. The exhibion fixtures, which the partitions, shelves, miches, and stages were put together in flexibility, play multiple roles as partitions dividing spaces, as furniture displaying art works, and as elements creating forms. The systematically arranged fixtures, also produce several visual axes and centers, which have visitors appreciate the works of art in various perspectives, hence create a unique environment.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.4
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• pp.95-112
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• 2013

Jangchungdan Park is now perceived as a mere park at the foot of Namsan mountain, but originally it was created to commemorate soldiers of Korean Empire on a site which name was Namsoyeong(南小營) during Joseon Dynasty. During the period of Japanese colonial rule, it was transformed into a park due to the rapidly changing circumstances, so the components expressing the validity of the colonial rule were introduced into the park. This paper examines the time sequential changes of Jangchungdan Park during the period of Japanese colonial rule, and the conclusions can be summarized as given below. Firstly, the park originally was a space to commemorate the soldiers who fought for the Korean Empire. It was built on formerly restricted area at the foot of Namsan Mountain in 1900, and it was arranged putting the ceremonial shrine Dansa (壇祠) as a central building and the annexes in the surroundings of it. The memorial ceremonies were held regularly in spring and autumn until 1909. Secondly, it became a city park for citizens of Gyeongseong-bu(the name of Seoul under the Japanese colonial rule). The authorities of Gyeongseong-bu reorganized Jangchungdan as a park in 1919, prohibited the performance of memorial ceremonies, and the existing buildings except the ceremonial shrine Dansa began to be used as park management facilities. Resting areas and amenities were supplemented for the usage of people from various backgrounds, and the large scale planting of cherry trees made the park a famous place to enjoy cherry-blossoms and other flowers in spring. Thirdly, it was reconstructed as a space to honor the influential personalities of Japanese colonial system. In 1932, Bankmun temple (博文寺) to commemorate Ito Hirobumi was constructed at a location that made it possible for a number of people to overlook Jangchungdan area. During that time, the buildings of traditional Joseon architecture were removed and reconstructed to serve as annexes to Bankmun temple. Due to the strategy to make Jangchungdan park a tourist attraction, Bankmun temple was included into the Gyeongseong sightseeing course, since the wide panorama of Jangchungdan Park and the whole city of Gyeongseong was opening from the temple. Various different components were introduced into Jangchungdan Park due to the rapidly changing circumstances; therefore the nature of the park was either altered or reproduced. Hopefully, the park rearrangement works will be executed paying respects to the memories of the past hereafter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.69-80
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• 2007

Among the photoactive semiconductors such as $TiO_2,\;ZnO,\;Fe_2O_3,\;WO_3,\;and\;CdSe,\;TiO_2$ is the most widely used as photocatalyst in different media, because of its lack of toxicity and stability. In this study, the effects of titanium dioxide were investigated to obtain the information of physiological change in rice plant. Light-adapted Chlorophyll flourescence index decreased and relative electron transport rate of rice leaves was activated by titanium dioxide under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}$ PAR (Photosynthetic active radiation). Relative electron transport rate of rice leaf treated with titanium dioxide 10 ppm was high in order of $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;2,200\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;450\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$ and titanium dioxide 10 ppm (45.1%), control (32.4%), diuron 10 ppm (15.3%) under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$. Titanium dioxide increased photosynthesis of the rice leaf under $13.6\;KJ\;m^{-2}\;day^{-1}$ UV-B only. With titanium dioxide 20 ppm, reduced UV-B ($0.15\;KJ\;m^{-2}\;day^{-1}$) intensity changed the induction of proteins and twenty-five proteins were identified. Among them, seventy proteins were up-regulated, four proteins were down-regulated and four proteins were newly synthesized. Function of these proteins was related to photosynthesis (52%), carbohydrate metabolism (4%), stress/defense (8%), secondary metabolism (4%), energy/electron transport (4%), and miscellaneous (28%).