• 제목/요약/키워드: Altitude of the sun

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Unrecorded moss species from Korean flora II

  • Yoon, Young Jun;Kim, Chul Hwan;Gorobets, Konstantin-V.;Sun, Byung-Yun
    • 식물분류학회지
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    • 제41권3호
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    • pp.235-241
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    • 2011
  • Five unrecorded species (Oedipodium griffithianum, Myurella tenerrima, Trachypus bicolor, Coscinodon humilis, Meteorium miquelianum subsp. atrovariegatum) with one unrecorded family and two unrecorded genera, were reported as new to the Korean moss flora. The monotypic family Oedipodiaceae consisting of a single genus and single species was distinguished from Splachnaceae by small plants that were 10 mm in length simple or sometimes branched, obovate-spathulate to ${\pm}$ orbicular, costa ending below the apex and entire margins except for the lower long-ciliate portion The species was first found at the top of the Mt. Seorak at an altitude of 1708 m. The two genera, Myurella and Coscinodon were found in the Korean Peninsula. Myurella tenerrima (Theliaceae) was found around the top of Jung-bong on Mt. Jiri. It was mixed with other mosses in the crevices of rocks in the alpine regions. The species is similar to M. sibirica, yet it can be distinguished by the position of papilla in the median laminal cells. Coscinodon humilis (Grimmiaceae) were found on the ridge of Mt. Gaya. C. humilis has a variety of hyaline apex according to leaf position and forms a capsule so it can be distinguished by family. Trachypus bicolor and Meteorium miquelianum subsp. atrovariegatum are unrecorded species. T. bicolor (Trachypodaceae) were found on the ridge of Mt. Gaya. T. bicolor is similar to T. humilis but distinguished by the costal lengths of the leaves. M. miquelianum subsp. atrovariegatum (Meteoriaceae) was found in Gageo-do. This species was distinguished by the plant form and morphology of stem leaves in the same genus.

A Comparative Study on the Habitat of Abies koreana Wilson between Mt. Jiri and Mt. Halla

  • lhm, Byung-Sun;Lee, Jeom-sook;Kim, Moon-Hong;Kim, Ha-Song
    • Plant Resources
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    • 제3권2호
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    • pp.138-147
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    • 2000
  • This examination of vegetation is conducted from June to Oct. 1999 through on the spot survey, centering on the habitat of Abies koreana around Imgeolryeong, Jangteomok, and Jeseokbong in Mt Jiri and Yeongsil path and Seongpanak path in Mt. Halla. Species composition tables of the Abies koreana community by altitude and slope in Mt. Jiri and Mt. Halla are made based on the community composition tables examined in quadrat. The Abies koreana-Saso quelpaertensis community in a west slope of Mt. Halla is found that Abies koreana of 4-6m in height forms subtree layer and that of 8-9m in height the tree layer and it reflects a difference between community structure by slope and main composition species. While the tree layer of Abies koreana community is 12-14 in height around the area of 1,290-1,560m above the sea of Imgeolryong and path from Baekmudong to Jangteomok, it is 8-12m in height in the area of 1,680-1,780m above the sea of path from Jangteomok to Jeseokbong. It means that community structure depends on area and attitude. This study finds out that commonly appearing composition species similar to coverage and presence are Lepisorus thunberianus, Quercus mongolica, Solidago virga-aurea var. asiatica, Ligularia fischeri, Carex lanceolata, Clintonia udensis, Magnolia sieboldii, Betula ermani, Acer pseudo-sieboldianum. As soil environment of surveyed area, pH of surveyed spots is similar in Mt. Jiri and Mt. Halla, electrical conductivity is higher in Mt Jiri, and contents of organic matter is relatively higher in a west slope of Mt. Jiri and Mt. Halla and lower in their south and west slopes. Contents of organic matter and total nitrogen show that the area of 1,550m above the sea in a west slope of Mt. Halla is some higher. For pH and contents of total nitrogen and organic matter, Mt. Halla is higher than Mt. Jiri but for electrical conductivity, Mt. Jiri is relatively higher than Mt. Halla.

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영농형 태양광 발전 솔라쉐어링에 따른 하부 일사량 변화의 해석 및 분석 (Simulation and Analysis of Solar Radiation Change Resulted from Solar-sharing for Agricultural Solar Photovoltaic System)

  • 이상익;최진용;성승준;이승재;이지민;최원
    • 한국농공학회논문집
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    • 제62권5호
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    • pp.63-72
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    • 2020
  • Solar-sharing, which is an agricultural photovoltaic system installing solar panels on the upper part of crop growing field, has especially drawn attention. Because paddy fields for cultivating crops are large flat areas, there have been various attempts to utilize solar energy for solar photovoltaic as well as growth of crops in agriculture. Solar-sharing was first proposed in Japan, and has been actively studied for optimization and practical uses. The domestic climate differs from the climate conditions in which the solar-sharing has been widely studied, therefore, it is required to develop the solar-sharing technology suitable for the domestic climate. In this study, a simulation model was developed to analyze the change of solar radiation resulted from the solar-sharing installation. Monthly solar illumination intensity and the change of illumination intensity according to the various conditions of solar panel installation were simulated. The results of monthly illumination analysis differed by altitude of the sun, which was related to season. In addition, it was analyzed that the monthly illumination decreased by up to 42% due to solar-sharing. Accordingly, it is recommended that solar-sharing should be installed as a way to maximize the efficiency of solar photovoltaic system while minimizing the decrease in solar radiation reaching the crops.

Accuracy Estimation of Electro-optical Camera (EOC) on KOMPSAT-1

  • Park, Woon-Yong;Hong, Sun-Houn;Song, Youn-Kyung
    • Korean Journal of Geomatics
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    • 제2권1호
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    • pp.47-55
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    • 2002
  • Remote sensing is the science and art of obtaining information about an object, area or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation./sup 1)/ EOC (Electro -Optical Camera) sensor loaded on the KOMPSAT-1 (Korea Multi- Purpose Satellite-1) performs the earth remote sensing operation. EOC can get high-resolution images of ground distance 6.6m during photographing; it is possible to get a tilt image by tilting satellite body up to 45 degrees at maximum. Accordingly, the device developed in this study enables to obtain images by photographing one pair of tilt image for the same point from two different planes. KOMPSAT-1 aims to obtain a Korean map with a scale of 1:25,000 with high resolution. The KOMPSAT-1 developed automated feature extraction system based on stereo satellite image. It overcomes the limitations of sensor and difficulties associated with preprocessing quite effectively. In case of using 6, 7 and 9 ground control points, which are evenly spread in image, with 95% of reliability for horizontal and vertical position, 3-dimensional positioning was available with accuracy of 6.0752m and 9.8274m. Therefore, less than l0m of design accuracy in KOMPSAT-1 was achieved. Also the ground position error of ortho-image, with reliability of 95%, is 17.568m. And elevation error showing 36.82m was enhanced. The reason why elevation accuracy was not good compared with the positioning accuracy used stereo image was analyzed as a problem of image matching system. Ortho-image system is advantageous if accurate altitude and production of digital elevation model are desired. The Korean map drawn on a scale of 1: 25,000 by using the new technique of KOMPSAT-1 EOC image adopted in the present study produces accurate result compared to existing mapping techniques involving high costs with less efficiency.

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도시지역 유인관측소 일조 관측환경 평가 모델 개발 (Development of Observational Environment Evaluation Model for Sunshine Duration at ASOSs Located in Urban Areas)

  • 김도용;김도형;김재진
    • 대기
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    • 제23권3호
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    • pp.275-282
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    • 2013
  • In this study, the numerical model was developed to evaluate the observational environment of sunshine duration and, for evaluating the accuracy and utility of the model, it was verified against the observational data measured at Dae-gu Automated Synoptic Observing System (ASOS) located in an urban area. Three-dimensional topography and building configuration as the surface input data of the model were constructed using a Geographic Information System (GIS) data. First, the accuracy of the computing planetary positions suggested by Paul Schlyter was verified against the data provided by Korea Astronomy and Space Science Institute (KASI) and the results showed that the numerical model predicted the Sun's position (the solar azimuth and altitude angles) quite precisely. Then, this model was applied to reproduce the sunshine duration at the Dae-gu ASOS. The observed and calculated sunshine durations were similar to each other. However, the observed and calculated sunrise (sunset) times were delayed (curtailed), compared to those provided by KASI that considered just the ASOS's position information such as latitude, longitude, and elevation height but did not consider the building and topography information. Further investigation showed that this was caused by not only the topographic characteristic (higher in the east and lower in the west) but also the buildings located in the southeast near the sunrise and the southwest near the sunset. It was found that higher building resolution increased the accuracy of the model. It was concluded that, for the accurate evaluation of the sunshine duration, detailed building and topography information around the observing sites was required and the numerical model developed in this study was successful to predict and/or the sunshine duration of the ASOS located in an urban area.

반고정식 PV 시스템의 운영 스케줄 도출 및 그에 따른 발전 효율 변화 고찰 (Optimal Operation Schedule of Semi-Fixed PV System and Its Effect on PV Power Generation Efficiency)

  • 곽인규;문선혜;허정호
    • 한국태양에너지학회 논문집
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    • 제37권6호
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    • pp.69-77
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    • 2017
  • The amount of solar irradiation obtained by a photovoltaic (PV) solar panel is the major factor determining the power generated by a PV system, and the array tilt angle is critical for maximizing panel radiation acquisition. There are three types of PV systems based on the manner of setting the array tilt angle: fixed, semi-fixed, and tracking systems. A fixed system cannot respond to seasonal solar altitude angle changes, and therefore cannot absorb the maximum available solar radiation. The tracking system continually adjusts the tilt angle to absorb the maximum available radiation, but requires additional cost for equipment, installation, operation, and maintenance. The semi-fixed system is only adjusted periodically (usually seasonally) to obtain more energy than a fixed system at an overall cost that is less than a tracking system. To maximize semi-fixed system efficiency, determining the optimal tilt angle adjustment schedule are required. In this research, we conducted a simulation to derive an optimal operation schedule for a semi-fixed system in Seoul, Korea (latitude $37.5^{\circ}$). We implemented a solar radiation acquisition model and PV genereation model on MATLAB. The optimal operation schedule was derived by changing the number of tilt angle adjustments throughout a year using a Dynamic Algorithm. The results show that adjusting the tilt angle 4 times a year was the most appropriate. and then, generation amount of PV system increased 2.80% compared with the fixed system. This corresponds to 99% compared to daily adjustment model. This increase would be quite valid as the PV system installation area increased.

섹스탄트를 이용한 개선된 선박 측위 알고리즘의 구현 (Implementation of Improved Ship Positioning Algorithm using Sextant)

  • 신희한;임재홍
    • 한국정보통신학회논문지
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    • 제21권6호
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    • pp.1243-1251
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    • 2017
  • 선박이 대양 항해 시 선박의 위치를 구하는 것은 안전 항해를 위해 매우 중요하다. 1990년대 이후 GPS(Global Positioning System) 항법의 발전으로 대부분의 선박들이 GPS를 이용하고 있다. 천문 항법은 대양항해 시 항법 수단으로 활용되었으나 계산과정이 복잡하고 시간이 많이 걸리며 해도에 작도를 해야 하는 어려움이 있었다. 그 결과, 활용성이 급격히 저하되었다. 본 논문에서는 기존 천문항법의 문제점을 개선하여 편리성과 활용성을 도모한 개선된 선박 측위 알고리즘을 제시하고 천문항법의 계산과정을 수식으로 정리하여 알고리즘을 소프트웨어로 구현하였다. 선박이 항해 시 태양의 고도, GHA, dec를 컴퓨터에 입력하면 선위가 경 위도 좌표로 화면에 전시된다. 본 논문의 결과, 개선된 방법으로 천문항법의 유용성을 확인할 수 있었으며 조난 시 훌륭한 항법 수단이 될 것이다.

Relationship between Preharvest Factors and the Incidence of Storage Disorders in 'Fuji' Apples during CA Storage

  • Kweon, Hun-Joong;Kim, Mok-Jong;Moon, Yong-Sun;Lee, Jin-Wook;Choi, Cheol;Choi, Dong-Geun;Lee, Dong-Hoon;Kang, In-Kyu
    • 원예과학기술지
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    • 제30권1호
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    • pp.50-55
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    • 2012
  • This study was carried out to evaluate the effect of pre-harvest factors on fruit quality and the incidence of storage disorders in 'Fuji' apple during CA storage. Incidence of storage disorders varied, depending on the growing regions, field conditions, and altitude of the orchards. Results indicated that fruit maturity may play a crucial role in the incidence and severity of flesh browning and watercore. The incidence of these storage disorders increased with fruit maturity until 180 days after full bloom (DAFB). In addition, occurrence of watercore was correlated with the incidence of flesh browning during CA storage. The incidence of flesh browning was positively correlated with the sum of the diurnal temperature range from September through October and amount of precipitation from August to October in 1996-1999 growing years. These results suggested that 'Fuji' apple should be harvested no later than 180 DAFB because the late harvested fruits were prone to development of watercore which was correlated with the incidence of flesh browing during CA storage in Korea.

Analysis of the MSC(Multi-Spectral Camera) Operational Parameters

  • Yong, Sang-Soon;Kong, Jong-Pil;Heo, Haeng-Pal;Kim, Young-Sun
    • 대한원격탐사학회지
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    • 제18권1호
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    • pp.53-59
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    • 2002
  • The MSC is a payload on the KOMPSAT-2 satellite to perform the earth remote sensing. The instrument images the earth using a push-broom motion with a swath width of 15 km and a GSD(Ground Sample Distance) of 1 m over the entire FOV(Field Of View) at altitude 685 km. The instrument is designed to haute an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data compression/storage. The MSC instrument has one channel for panchromatic imaging and four channel for multi-spectral imaging covering the spectral range from 450nm to 900nm using TDI(Time Belayed Integration) CCD(Charge Coupled Device) FPA(Focal Plane Assembly). The MSC hardware consists of three subsystem, EOS(Electro Optic camera Subsystem), PMU(Payload Management Unit) and PDTS(Payload Data Transmission Subsystem) and each subsystems are currently under development and will be integrated and verified through functional and space environment tests. Final verified MSC will be delivered to spacecraft bus for AIT(Assembly, Integration and Test) and then COMSAT-2 satellite will be launched after verification process through IST(Integrated Satellite Test). In this paper, the introduction of MSC, the configuration of MSC electronics including electrical interlace and design of CEU(Camera Electronic Unit) in EOS are described. MSC Operation parameters induced from the operation concept are discussed and analyzed to find the influence of system for on-orbit operation in future.

A Study on Anion Generation according to Vertical Structures of Tree

  • Kim, Jeong-Ho;Oh, Deuk-Kyun;Seo, Yoo-Hwan;Park, Jae-Hyeon;Yoon, Yong-Han
    • 한국환경과학회지
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    • 제25권10호
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    • pp.1369-1379
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    • 2016
  • This research assessed the disparity in anion generation according to the vertical structure of a Zelkova Serrata tree for the purpose of creating a pleasant and green city environment. Measurements for the study were conducted between July and August of 2014 in Chung-ju in the central region of the Republic of Korea. The average anion generation of vertical structure trees during active photosynthesis periods was: L Section ($839.0ea/cm^3$) > M Section ($664.6ea/cm^3$) > U Section ($472.0ea/cm^3$). According to DMRT analysis, significant difference was found in the average between the L, or M Locations and the U Locations. During dormant photosynthesis periods, records showed that the anion production at the M Location ($1,212.5ea/cm^3$) > L Location ($1,050.4ea/cm^3$) > H Location ($844.1ea/cm^3$), According to DMRT analysis, the difference within each location was significant for ${\alpha}=0.05$. In a comprehensive analysis of the weather factors in each vertical structure, anion generation during active photosynthesis periods showed a positive correlation with solar radiation and a negative correlation with wind speed. Dormant photosynthesis periods showed negative correlations with both solar radiation and temperature, and positive correlations with relative humidity and wind speed. Predictions from a multicenter retrospective study showed that during active photosynthesis periods, $Y_1=282.443X_1+512.07$, and $Y_2=314.337X_1+16.913X_2$, while during dormant photosynthesis periods, $Y_1=391.009X_1+840.043$, and $Y_2=351.412X_1+32.765X_2$.