• Korean Journal of Remote Sensing
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• v.35 no.6_1
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• pp.987-997
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• 2019

Recently the demand for drones is rapidly increasing, as developing Unmanned Aerial Vehicle (UAV) and growing interest in them. Compared to traditional satellite and aerial imagery, it can be used for various researches (environment, geographic information, ocean observation, and remote sensing) because it can be managed with low operating costs and effective data acquisition. However, there is a disadvantage in that only a small area is acquired compared to the satellite and an aircraft, which is a traditional remote sensing method, depending on the battery capacity of the UAV, and the distance limit between Ground Control System (GCS) and UAV. If remote control at long range is possible, the possibility of using UAV in the field of remote sensing can be increased. Therefore, there is a need for a communication network system capable of controlling regardless of the distance between the UAV and the GCS. The distance between UAV and GCS can be transmitted and received using simple radio devices (RF 2.4 GHz, 915 MHz, 433 MHz), which is limited to around 2 km. If the UAV can be managed simultaneously by improving the operating environment of the UAV using a Long-Term Evolution (LTE) communication network, it can make greater effects by converging with the existing industries. In this study, we performed the maximum straight-line distance 6.1 km, the test area 2.2 ㎢, and the total flight distance 41.75 km based on GCS through LTE communication. In addition, we analyzed the possibility of disconnected communication through the base station of LTE communication.

• Journal of Ginseng Research
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• v.26 no.3
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• pp.159-164
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• 2002

Experiments were carried out to select the rusty tolerance lines in 39 inbred lines of ginseng cultivated in field, among them, 7 lines showed low degree of rusty root while 7 lines showed high degree of rusty root. In order to select marker elements among mineral nutrients for rusty ginseng root, we combined 5 groups as follows : Ⅰ (healthy-root of low rusty degree lines vs. rusty-root of high rusty degree lines), II (healthy-root vs. rusty-root in low rusty degree lines), Ⅲ (healthy-root vs. rusty-root in high rusty degree lines), Ⅳ (low rusty degree lines vs. high rusty degree lines in rusty-root), Ⅴ (low rusty degree lines vs. high rusty degree lines in healthy-root), and analyzed mineral nutrition at different root parts. The contents of mineral nutritions in stele and cortex were not different between healthy lines and rusty lines, and between healthy roots and rusty roots, but that in branch and fine roots were not a tendency. The contents of Fe, Na and Al in epidermis were higher in rusty-root than healthy-root. Also, the contents of Fe and Al in epidermis of high rusty degree lines (HRL) were higher than those of low rusty degree lines (LRL) in healthy-roots and rusty-roots, and so we suggest Fe and Al as markers to select low rusty degree ginseng lines.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.975-987
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• 2021

Potential habitat mapping of Meretrix lyrata which is found in large parts of South East Asian tidal flat was carried out to find out causes of collective death. Frequency Ratio (FR) method, one of geospatialstatistical method, was employed with some benthic environmental factors; Digital elevation model (DEM) made from Landsat imagery, slope, tidal channel distance, tidal channel density, sedimentary facesfrom WorldView-02 image. Field survey was carried out to measure elevation of each station and to collect surface sediment and benthos samples. Potential habitat maps of the all clams and the juvenile clams were made and accuracy of each map showed a good performance, 76.82 % and 69.51 %. Both adult and juvenile clams prefer sand dominant tidal flat. But suitable elevation of adult clams is ranged from -0.2 to 0.2 m, and that of juvenile clams is ranged from 0 to 0.3 m. Tidal channel didn't affect the habitat of juvenile clams, but it affected the adult clams. In the furtherstudy, comparison with case of Korean tidal flat will be carried out to improve a performance of the potential habitat map. Change in the benthic echo-system caused by climate change will be predictable through potential habitat mapping of macro benthos.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.151-163
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• 2022

This study was conducted to promote organic fertilizer(s) that sustain soil productivity for corn production and protect the environment as required by the Act on the promotion of eco-friendly agriculture. It was conducted at the research station of the Organic Agriculture Division of the National Institute of Agricultural. The treatments consisted of Compost (Com), Bokashi as fermented organic fertilizer (FOF), and mixed expeller pressed cake (PC). They were applied at 174 kg N /ha to field corn, together with a 'no fertilizer' check in Randomized Complete Block Design. At eight weeks after transplanting (WAT) corn, compost increased soil carbon (C) and nitrogen (N) to 7.48 and 0.76 g/kg respectively, while other fertilizers maintained the initial levels (before treatment application). At corn harvest (13 WAT), soil chemical properties (total C, total N, pH, electrical conductivity, P₂O₅, Ca, K, and Mg) were similar among all organic fertilizer treatments. For soil respiration, FOF increased soil CO₂ respiration by 31-76% above other fertilizer treatments. However, there were no prominent changes in the trends of CH₄ fluxes following the two mechanical weeding operations. Fermented organic fertilizer affected N₂O emissions between 87-96% lower than other fertilizer treatments. Compared to the initial microbial densities, FOF increased fungi and actinomycete colony foming unit by 25 and 16% at harvest. Therefore, the additional potential of improving soil biological fertility and local availability of raw materials make FOF a better option to sustain soil productivity while protecting the environment.

• Industry Promotion Research
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• v.7 no.3
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• pp.85-91
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• 2022

In modern society, the field of life is expanding to complex and diverse fields according to changes in lifestyle. As people's consciousness also changes, various social problems are involved, and countermeasures are being taken in various ways. In particular, as the issue of school violence has become a subject of interest, government-related ministries have jointly set up a reporting center and professional counselors are receiving and consulting on damage reports. Counselors experience mental and physical exhaustion in the course of their work. Therefore, the need to contribute to effective counseling work is raised by studying the factors that cause burnout. This study collected the experiences of 10 counselors working at 117 reporting centers from February 2019 to May 2020 through interviews and analyzed them with Colaizzi's phenomenological research method. The exhaustion factors derived from the results of the study were first experiences such as conflict between counselors during the period of institutional integration in the "117 reporting center experience", and secondly, professional counselors experienced emotional exhaustion, inhumanization, and lack of achievement. In order to prevent and overcome the exhaustion factors of counseling agents, it was necessary to prepare measures to promote fraud. This is expected to be useful data for improving the working environment of special job counselors in the era of industrialization and informatization in which various anonymous counseling methods are used.

• Journal of Marine Life Science
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• v.1 no.1
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• pp.8-17
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• 2016

The family Pristiophoridae belonging to the order Pristiophoriformes consists of about 8 species and 2 genera in the world. Among them, only one species (Pristiophorus japonicus) is distributed in northwestern Pacific. The family is characterized by having an elongated and flattened rostrum with laterally projecting a low of sharp teeth. In order to clarify variability of local populations of P. japonicus, we investigated 16 individuals collected from four locations (Korea, n=6; Miyagi, n=1; Kochi Pref., n=1; Okinawa, n=8) for morphological and molecular analyses. Morphological analysis showed that there may exist three morphotypes, of which A morphotype (Korea, Miyagi, Kochi Pref.) has a short snout (26.8% of TL), being most similar to syntypes of P. japonicus. On the other hand, B morphotype (Okinawa) has a long (31.7% of TL) and wider snout (snout width at nostrils 5.2 times pre-oral length) and, C morphotype (Okinawa) has a long (31.7% of TL) and narrower snout (6.3 times). Molecular analysis using mitochondrial DNA cytochrome b DNA sequences (386 base pairs) showed that the K2P distance between A and C morphotypes were 2.1~2.7%, but those within A morphotype were 0.0~0.5%. We identified A morphotype as P. japonicus, and designated B and C morphotypes as Pristiophorus sp. 1 and Pristiophorus sp. 2, respectively. Further studies are required to elucidate the taxonomic status of two morphotypes of the sawshark in Okinawa.

• The Journal of Natural Sciences
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• v.7
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• pp.91-101
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• 1995

To establish the simple and practical test method of estimating resistance of rice varieties against rice leafblight, trials were made to correlate among the four test methods such as true resistance test,secondaryinfection test, secondary epidemic test and field test. The results obtained through the experiment on 25 ricevarieties and 3 pathogenic isolates designated to HB9O11, HB9022 and HB9033 can be summarized asfollows. 1 .Based on the results of true resistance test, 25 rice varieties can be classified into four groups:1 )Samgang variety group ;resistant to HB9011, 13 varieties, 2)Pungsan variety group ; resistant to HB9011 and HB9022, 5 varieties, 3)Samgang variety group ; resistant to all three isolates, 2 varieties, 4)Unbongvariety group: sensitive to all three isolates, 12 varieties. 2. The responses of rice varieties to isolates showed some discrepancies among on the test methods. These examples were found in 3 varieties including Yeongdeog varieties to HB9011, 3 varieties including Taebaeg variety to HB9022 and Taebaek vaieties to HB9033. 3. Correlation coefficiences between the secondary infection test and the secondary epidemic test for HB9011, HB9022 and HB9033 were 0.972, 0.894 and 0.919, respectively. It suggests that the two methods are not significantly different so that one of the two methods are not significantly different so that one of the two methods can be omitted from resistant test without affecting the result. 4. Between the true resistance test and the field test at the disease common area, there were no significant correlations. Unbong, Chucheong and Yeongdeog varieties are appeared as resistant varieties in the true resistant test, but their responses in the field test were different and appeared as sensitive varieties. 5. The disease index was used to express theresults from four test methods. The disease index was calculated as the sum of each numerical values of theresults from the four test methods by giving the same weights(0 to 25)to each test method. If the disease index for certain variety is less than 15, then the variety is considered to be resistant. 4 varieties such as Seohae, Hwajin, Yeongdeog and Pungsan varieties-disease indices were less than 15 were selected as field resistance varieties.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.2
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• pp.64-75
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• 2022

The purpose of this study is to illuminate the meaning of the soundscapes of two bells, Daeheung-dong Cathedral and Sungsimdang in Eunghang-dong, which are landmarks and attractions in the historic downtown of Daejeon. The study was conducted through field research and recordings, as well as literature studies of related documents and soundscape theory. Daejeon city was developed along with Daejeon Railway Station during the Japanese colonial period in the early 20th century. As the Chungnam Provincial Office moved to Daejeon, Daeheung-dong and Eunhang-dong in Jung-gu, located near Daejeon Station, developed significantly and formed the city centre. As major administrative agencies moved to Seo-gu in the 1990s, the downtown area of Daejeon was on a path of decline, and the decline accelerated with the development of Sejong city. Meanwhile, Daeheung-dong Cathedral and Sungsimdang, founded by refugees during the Korean War, firmly protected the historic downtown area of Daejeon, where the natives left. Daeheung-dong Cathedral, established during the Japanese colonial period, is a local landmark with a history of 100 years in 2019. Sungsimdang, which was created with the backdrop of the Korean War, is also a historical and cultural asset with a history of 60 years and a local landmark selected as the No. 1 tourist attraction in Daejeon. This research, which started from the sound of the bells of Daeheung-dong Cathedral, heard even in the neighboring residential areas, led to the discovery of the bells of Sungsimdang in Eunhang-dong, located across the street. In this paper, the bells of Daeheung-dong Cathedral and Eunhang-dong Sungsimdang have characteristics of soundmarks according to R. Murray Schafer's soundscape sound category. Furthermore, this paper attempted to analyze the meaning of the two bells according to the relatively recent EU soundscape definition. These two bells are signal sounds at the surface level, but are the sound marks of the historic downtown area of Daejeon at the deep level. Although there are outward differences in size, scale, frequency, and famousness, these two bells share a meaning in terms of locality and good influence with the historicity and spatiality of a special relationship. The implication of this study is that the two places should be preserved as local historical and cultural assets not only as visual landmarks but also as sound marks in the urban regeneration or urban development of Jung-gu, Daejeon.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.2
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• pp.102-117
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• 2009

This study was carried out to investigate the extent to which benthic environment of Ulsan Bay was disturbed by organic materials and trace metals from the megacity and industrial complex. Field survey for benthic environment and macroinvertebrate community was seasonally conducted from February to November 2006 at nine stations covering the inside and outside of the bay. TOC was on average 1.7% while four (As, Cu, Pb, Zn) out of seven trace metals measured exceeded the Effects Range Low (ERL) in most of the stations. Total number of species sampled was 199 and mean density was 4,578 ind./$m^2$, both of which were greatly dominated by the polychaetes. Dominant species were Aphelochaeta monilaris (22.6%), Ruditapes philippinarum (17.1%), Magelona japonica (12.2%), Lumbrineris longifolia (9.9%) and their distribution was ruled by the difference in the benthic environmental condition of each station. From the multivariate analyses, four stational groups were identified: northern part of the bay, middle and lower part of the bay, the intersection of Taewha River and Gosa stream and outside of the bay. As a result, the community heterogeneity of inner bay was much more greater than that of outer bay. SIMPER analysis showed that four groups were represented by R. philippinarum-Capitella capitata, A. monilaris-Balanoglossus carnosus, Sinocorophium sinensis-Cyathura higoensis and M. japonica-Ampharete arctica, respectively. Spatio-temporal changes of macroinvertebrate communities in Ulsan Bay were closely related to those of depth, mean grain size and organic content, and Zn was also a meaningful factor in that context.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.238-245
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• 1998

The reasonable level of nitrogen fertilizer is a key factor to reduce environmental contamination as well as to increase crop yield and quality. The treatments are $N=42kg\;10a^{-1}$, $N=48kg\;10a^{-1}$, $N=54kg\;10a^{-1}$. $N=60kg\;10a^{-1}$. $N=72kg\;10a^{-1}$ and $N=150kg\;10a^{-1}$. Analytical results of yield and quality of tea leaves harvested the second time are summarized as follows: The soil of experimental field was higher in organic matter($49.9g\;kg^{-1}$) and available phosphate($937mg\;kg^{-1}$) compared to the general field but lower in pH(5.07) compared to the general field. When the amount of nitrogen fertilizer application was raised, the yield of tea leaves, the content of nitrogen, total free amino acids, caffeine and chlorophyll increased: however, the yield of tea leaves increased to excessive levels. On the other hand, the increased level of nitrogen fertilizer did not show any difference in the contents of vitamin C and tannin. Eleven kinds of amino acids were isolated from second harvested leaves of tea where the content of theanine occupied over 50%, and content of $665{\sim}763mg\;100g^{-1}$. The contents of fatty acids and catechin did not show correlation with application level of nitrogen fertilizer. The content of fatty acid was produced $1,742{\sim}2,643mg\;100g^{-1}$, and content of catechin was produced 12.47~13.54%. In scoring test, $N=60kg\;10a^{-1}$ treatment was 0.5~6.0 point higher compared to other treatments. Consequently, $N=60kg\;10a^{-1}$ is considered to be the best level of nitrogen fertilizer in terms of decreased environmental contamination as well as to increase crop yield and quality.