• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.325-331
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• 2014

The purpose of this study was to establish the proper sowing time and planting density of cowpeas for labor-saving cultivation. Experiments were carried out in Naju, Jeonnam Province (Latitude $35^{\circ}$ 04' N, Longitude $126^{\circ}$ 54' E) during 2012 and 2013. The intermediate-erect type strains used in this study were Jeonnam1 and Jeonnam2. Sowing was performed five times between June 25 and August 5 at approximately 10-day intervals in order to establish proper sowing time, and sowed at 5,000, 10,000, 15,000, and 20,000 plants per 10a to establish proper planting density. The days from sowing to first flowering was shortest (32 days) in plants sowed on July 25 and became longer for plants sowed on or around July 25. The days from sowing to first flowering was longest (41 days) in plants sowed on June 25. The days from first flowering to first maturing was shortest (8 days) in plants sowed on June 25 and, became considerably longer at later sowing dates. The days from first maturing to first harvesting ranged from 8 to 10 days, with little difference among the sowing periods. Plants sowed on August 5 harvested at the same time, and plants sowed between June 25 and July 25 were harvested either three or two times. The yield was highest in plants sowed on July 25: 209 kg/10a was harvested for Jeonnam1 and 221 kg/10a for Jeonnam2. Furthermore, harvested at the same time enabled when the harvesting was delayed for around 15 days because the share of the seeds first harvested was highest (91%). The proper planting density was estimated to be 15,000 plants/10a, showing the highest yields of 199 kg/10a for Jeonnam1 and 224 kg/10a for Jeonnam2.

• Journal of the Korean Institute of Navigation
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• v.25 no.1
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• pp.77-91
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• 2001

According to the many ancient literatures, it is said to be that Merchant Prince, Chang Pogo in unification Silla had traded with not only China, Japan but also Arab-Islam Countries, but unfortunately there is no definite records about this. Therefore in this study the writer would like to presume the sea routes of Merchant Prince, Chang Pogo in a unification Silla. For the purpose of this study the writer would like to study the reference books and materials regarding to the sea routes of prehistoric age and ancient three countries of Kingdoms and unification Silla. Especially the writer consider “The Work of Routes and Kingdoms” of Ibn Khurdarhbih regarding to the ancient sea routes of Korea, China, Arab-Islam Countries, and also the writer consider the ancient sea routes of Tang Dynasty in China and Ryukyu Kingdom in Japan. About this methodology of this study, the writer believe that the sea routes of today is the results of ancient sea routes, and this ancient sea routes could not be changed forever except special circumstance. According in this study the writer would like to persume the sea routes of Merchant Prince, Chang Pogo using like this methodologies. This presumption of the writer is originated on the basis of The Work of Routes and Kingdoms written by ancient Arabian Geographer, Ibn Khurdadhbih in the early years of 9th century. The Work of Routes and Kingdoms is geography, and the principal contents of this geography are the activities of Arab-Islam merchants and Chinese Merchants between Arab-Islam countries and China from 9th century to 11th century by ancient sea routes. But surprisingly in this geography, Silla was marked, and another ancient Arabian geogrpher, Al-Biruni marked Silla on his map, Qanun Al-mas'udi in the 9th century, and also another ancient Arabian geographer, Al-Idrisi marked Silla on his map in the 11th century. Especially Al-Biruni expressed the longitude and latitude of Silla on his map, he expressed Silla as following. “at the extreme end of China toward the East and few people travelled to it by sea”. Therefore the writer would like to presume that Arab-Islam merchants had traded with unification Silla in the 9th century, and also Merchant Prince, Chang Pogo had traded with not only China, Japan but also Arab-Islam Countries using above ancient sea routes in the 9th century.

• Economic and Environmental Geology
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• v.36 no.4
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• pp.305-312
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• 2003

This study was performed to delineate the subsurface geology, geologic structure, and distribution pattern of the Palgongsan granitic body, and to reveal the relationship between the Kyeongsang basin and Yongnam massif by gravity survey. The study area is located between the latitude of 35$^{\circ}$45'-36$^{\circ}$21'N and longitude of 128$^{\circ}$15'-129$^{\circ}$00'E. Total of 966 gravity data measured by Seoul National University, KlGAM(Korea Institute of Geology, Mining ＆ Materials), Pusan National University and Yonsei University were used. The Bouguer gravity anomaly in the study area ranges from -12.88 to 26.01 mgal with a mean value of 11.27 mgal. A very low anomaly zone is located in the Yongnam massif in west of the study area. The anomaly value increases going from west to east. A low anomaly distribution in Palgongsan granite and Yongnam massif is interpreted as the effect of their lower density than that of Kyeongsang Super Group. Power spectrum analysis is applied to evaluate the average depth of basement the Kyeongsang Basin and Conrad discontinuity from gravity anomaly. The average depths of density discontinuities are calculated 10.45 km and 4.9 km, and these are interpreted as Conrad discontinuity and depth of basement of the Kyeongsang Basin, respectively. The depth of Palgongsan granite is derived by means of 2-dimensional modeling and it decreases gradually toward the east. The gravity anomaly east of the study area decreases abruptly due to Shingryeong fault and Nogosan ring fault. Two deepest and sharp roots of Palgongsan granite are recognized by 2-dimensional modeling of each profiles. The depths of those roots are 5.3 km on a profile AA' and 7 km on a profile BB' which is the maximum depth of Palgongsan granite. Small granitic bodies are also seen to be intruded around the Palgongsan granite. The root of Palgongsan granite is shown by 3-dimensional analysis based on the interpolation of 2-dimensional modeling along each profiles to exist in the southwest vicinity of Palgongsan granite. The total volume of Palgongsan granite is approximately 31.211 $Km^3$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.204-212
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• 2019

The optimal application rate of a controlled release fertilizer (CRF) on the growth, yield, and seeding time of rice grown on seedling trays was investigated. The experimental field was located at $37^{\circ}22^{\prime}10^{{\prime}{\prime}}N$ latitude and $127^{\circ}03^{\prime}85^{{\prime}{\prime}}E$ longitude in Hwaseong, Gyeonggi-do, Republic of Korea. The soil in the paddy field was a clay loam. The CRF used in the experiment contained $300g\;kg^{-1}$ of nitrogen, $60g\;kg^{-1}$ of phosphate, and $60g\;kg^{-1}$ of potassium, respectively. The CRF was applied at the rate of 0, 200, 300, 400, 500, and 600 grams on rice seedling tray compared with the field application based on soil testing (control), respectively. The CRF can be applied as single application(which can replace basal fertilizer application and two top dressing application) directly to the seedling tray, and showed the minimum release at the seedling period. Considering the plant growth, nitrogen use efficency and yield of rice, the optimal application rate of developed CRF was 500 g per seedling tray and the yield of rice at this application rate was $4.92{\sim}5.04Mg\;ha^{-1}$. The regression formula between the rice yield and application rates of CRF was as follows ; "$Y=0.0002{\chi}^2+0.0963{\chi}+411.6$($R^2$ : 0.9922) in 2010 and $Y=8E-6{\chi}^2+0.2723{\chi}+344.04$($R^2$:0.9864) in 2011, Y : Rice yield ($Mg\;ha^{-1}$), ${\chi}$ : Application rate (grams) of controlled release fertilizer". The optimum application rates of CRF per rice seedling tray by regression formula was 498 grams in 2010 and 513 grams in 2011.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.470-476
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• 2014

The purpose of this study was to investigate the effects of sowing time on ecological responses, growth, and yields of cowpeas grown in plastic greenhouses in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (Latitude $35^{\circ}$ 04' N, Longitude $126^{\circ}$ 54' E) during 2012 and 2013. The intermediate-erect type strains used in this study were Jeonnam1 and Jeonnam2. Sowing was performed between mid-March and mid-August at intervals of one month. The days from sowing to emergence was significantly higher for the mid-March sowing (12 days) but no significant differences were observed among the other sowing dates (3 to 4 days). The days from sowing to first flowering were shorter for sowing dates between mid-March and mid-July because sowing time was delayed and then were lengthened again at mid-August sowing; the days were longest at mid-March sowing (around 75 days) and were shortest at mid-July sowing (30 days). The days from first flowering to harvesting were short for the sowing dates between mid-March and mid-May (24 to 28 days) but were relatively long for subsequent sowing dates (35 to 38 days). Stem and peduncle lengths were relatively long for the mid-April and mid-August sowing dates. Main-stem node number was highest for the mid-June sowing. Branch number per plant was highest for the mid-March sowing. The mid-March sowing displayed the highest number of pods per plant as well as the heaviest seed weight. Yield per 10 ares was highest for the mid-March sown Jeonnam1 and the Jeonnam2 strains (340 and 367 kg respectively), and then tended to decrease due to subsequent delays in sowing.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.335-344
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• 2023

Brachydiplax chalybea flavovittata, a climate-sensitive biological indicator species, was first observed and recorded at Jeju Island in Korea in 2010. Overwintering was recently confirmed in the Yeongsan River area. This study was aimed to predict the potential distribution patterns for the larvae of B. chalybea flavovittata and to understand its ecological characteristics as well as changes of population under global climate change circumstances. Data was collected both from the Global Biodiversity Information Facility (GBIF) and by field surveys from May 2019 to May 2023. We used for the distribution model among downloaded 19 variables from the WorldClim database. MaxEnt model was adopted for the prediction of potential and future distribution for B. chalybea flavovittata. Larval distribution ranged within a region delimited by northern latitude from Jeju-si, Jeju Special Self-Governing Province (33.318096°) to Yeoju-si, Gyeonggi-do (37.366734°) and eastern longitude from Jindo-gun, Jeollanam-do (126.054925°) to Yangsan-si, Gyeongsangnam-do (129.016472°). M type (permanent rivers, streams and creeks) wetlands were the most common habitat based on the Ramsar's wetland classification system, followed by Tp type (permanent freshwater marshes and pools) (45.8%) and F type (estuarine waters) (4.2%). MaxEnt model presented that potential distribution with high inhabiting probability included Ulsan and Daegu Metropolitan City in addition to the currently discovered habitats. Applying to the future scenarios by Intergovernmental Panel on Climate Change (IPCC), it was predicted that the possible distribution area would expand in the 2050s and 2090s, covering the southern and western coastal regions, the southern Daegu metropolitan area and the eastern coastal regions in the near future. This study suggests that B. chalybea flavovittata can be used as an effective indicator species for climate changes with a monitoring of their distribution ranges. Our findings will also help to provide basic information on the conservation and management of co-existing native species.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.2
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• pp.129-139
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• 2002

Fish distribution characteristics are essential to assess and estimate fisheries resources in a particular area. The primary goal of this study is to determine the distribution characteristics by the bottom trawling in the Yellow Sea west of South Korea. The surveys were carried out between 33$^{\circ}$00'N~37$^{\circ}$00'N latitude and 124$^{\circ}$00'E~126$^{\circ}$00'E longitude at EEZ(Exclusive Economic Zone) of Korea in Yellow Sea on May and August, 1999 and April, 2000. The ships used in this survey were the R/V Chung-kyeong(G/T 300) and R/V Dong-baek(G/T 1,050) of Yeosu National University. The results obtained can be summarized as follows 1. From the trawl data the fisheries resources are seriously decreasing through most of the species(about more 50%) have been appeared only one time at the bottom trawl on April, 2000. The total fish species caught by the trawl net during the 3 times survey were 106 species and a few species(dominant species) of these occupied 50~90% of the quantity of the total quantity by number or by weight. Among the dominant species the tanaka's snailfish was recorded to be the most dominant species in the survey area. The fish species in the Yellow Sea were clustered according to the regions. They clustered in two or three partes to the south-north direction in the spring season and clustered in two parts to the on-off shore direction of the shore in the summer season. Most of the fish caught at the the trawl net with cover-net(30.3mm) were small sized. They were shorter than 15 cm in length and the extruding rate of the cod-end which was 60mm mesh size ranges about 90%. 2. The densities of the number and weight per unit volume derived from the total catches sampled in April, 2000 survey were $1532.2{\times}10^{-6}fish/m^3$ and $39.55{\times}10^{-6}kg/m^3$, respectively. 3. The density variation of fish population between 1999 and 2000 showed a slight tendency to increase.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.125-130
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• 2008

This study analyzed the growth, seed quality, and yield of major early-maturing soybean cultivars by comparing them in order to utilize the research results in the selection of early-maturing soybean cultivars in multi-cropping farms in the Southern area. This field trial was conducted at Naju region (latitude $35^{\circ}04'N$, longitude $126^{\circ}54'E$), Jeonnam, with planting on June 15. The maturing date for Keunol-kong and Hwaseong-put-kong was found to be around September 12, which was earlier than other cultivars. Thus, there were advantages to introducing a cropping system as well as having good seed quality and high yield. On the other hand, the maturing date for Saeol-kong and Sinrok-kong was found to be around September 20, which was a little bit late; however, the seed quality of the cultivars was good and they had a high yield. Therefore, if we want to sow the following crops of soybeans around mid-September, Keunol-kong and Hwaseong-put-kong are advantageous, while for the seeding around late September, Saeol-kong and Sinrok-kong would be good. This study was also performed to identify the limitation time for early harvesting by reviewing seed quality and yield of major early-maturing soybean cultivars according to early harvesting. When harvesting Keunol-kong on September 6, which was six days earlier than the optimal harvesting time (September 12), there was no difference in seed weight, yield, or seed quality than those of the harvested at the optimum maturing time. As for Saeol-kong, when harvesting on September 18, which was six days earlier than the optimal harvesting time (September 24), there was no difference in seed weight, yield, or seed quality than those of the harvested at the optimum maturing time. Therefore, the stable limitation time for early harvesting of Keunol-kong and Saeol-kong was concluded to be six days earlier than the optimal harvesting time.

• (The)Study of the Eastern Classic
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• no.33
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• pp.31-56
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• 2008

Jang Hyeon-gwang(張顯光, 1554-1637), whose pseudonym or courtesy name is 'Yeoheon(旅軒)', had made a thorough study on the intrinsic nature of Neo-Confucianism in a more sincere fashion, when comparing him with other Neo-Confucianists in Joseon period. Also he was a renowned scholar who expanded its philosophical system in-depth. Yeoheon thereby had strengthened his philosophical system accordant with the Great Learning(大學) and Doctrine of the Mean(中庸), which are the fundamental systems of Neo-Confucianistic education. Based on such considerations, Yeoheon's thought on education can be illuminated from three different perspectives. First, Yeoheon deepened his a theory of good governance by a virtuous ruler(聖人君主論, pronounced, 'Seongingunjuron') as the standard of education. Essentially, his theory pursues Refraining from desire, and preserving the laws of nature(存天理?人欲, pronounced, 'Joncheolliarinnyok'), and put emphasis on ethical awakening, and the governance through a virtue of moral excellence. Second, Yeoheon stressed the learning theories related to 'sincerity' or true heart(誠) and 'piety' or 'respect'(敬)) as the form of education(誠敬, pronounced, 'Seonggyeong'). Also he expounded that people needs "to establish a ground of Respect and Sincerity in their mind." He recognized the differences between the two virtues, meanwhile, however, he understood it as in an identical context. Third, Yeoheon advocated harmony between separation and integration(分合, pronounced, 'Bunhap') as a method for education. Through his unique 'Discourse on Longitude and Latitude', dubbed, 'Li-Gi Gyeongwiseol (理氣經緯說) in which the principle(Li, 理) is equal to the intrinsic energy or material force(Gi, 氣), he maintained his view on the Doctrine of the Mean, in that he was not inclined to either sides according to the logic of Change(易, pronounced 'Yeok'). When reviewing Yeoheon's contemplation in education in the meaning of modern education, he laid the standards for education on the establishment of morality, and he also provides us with an idea which induces us to look through the form and method for education from the perspective of Doctrine of the Mean. In short, Yeoheon's view on education embodies wisdom of traditional Neo-Confucianistic Education having consistency, and it provides for an implication of the review of the importance of the balance in relation to methodological bias toward confusion in the standards for modern education, and unsystematic contents therein.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1125-1139
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• 2022

In an unmanned aerial vehicles (UAVs) system, a physical offset can be existed between the global positioning system/inertial measurement unit (GPS/IMU) sensor and the observation sensor such as a hyperspectral sensor, and a lidar sensor. As a result of the physical offset, a misalignment between each image can be occurred along with a flight direction. In particular, in a case of multi-sensor system, an observation sensor has to be replaced regularly to equip another observation sensor, and then, a high cost should be paid to acquire a calibration parameter. In this study, we establish a precise sensor model equation to apply for a multiple sensor in common and propose an independent physical offset estimation method. The proposed method consists of 3 steps. Firstly, we define an appropriate rotation matrix for our system, and an initial sensor model equation for direct-georeferencing. Next, an observation equation for the physical offset estimation is established by extracting a corresponding point between a ground control point and the observed data from a sensor. Finally, the physical offset is estimated based on the observed data, and the precise sensor model equation is established by applying the estimated parameters to the initial sensor model equation. 4 region's datasets(Jeon-ju, Incheon, Alaska, Norway) with a different latitude, longitude were compared to analyze the effects of the calibration parameter. We confirmed that a misalignment between images were adjusted after applying for the physical offset in the sensor model equation. An absolute position accuracy was analyzed in the Incheon dataset, compared to a ground control point. For the hyperspectral image, root mean square error (RMSE) for X, Y direction was calculated for 0.12 m, and for the point cloud, RMSE was calculated for 0.03 m. Furthermore, a relative position accuracy for a specific point between the adjusted point cloud and the hyperspectral images were also analyzed for 0.07 m, so we confirmed that a precise data mapping is available for an observation without a ground control point through the proposed estimation method, and we also confirmed a possibility of multi-sensor fusion. From this study, we expect that a flexible multi-sensor platform system can be operated through the independent parameter estimation method with an economic cost saving.