• Journal of agriculture & life science
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• v.50 no.1
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• pp.105-115
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• 2016

This study was carried out to establish the optimum forest management plan for the Cryptomeria japonica plantations in southern inland and Jeju island in Korea. Sixty seven circular sample plots of 0.04ha were established and we surveyed vegetation structure and growth characteristics from three layers(upper, middle, and lower). As a result of cluster analysis obtained by importance values of each tree species, the community type of C. japonica stands were classified into C. japonica group(C1) and C. japonica-C obtusa group. C. obtusa community were also sbudivided into P. thunbergii-Q. serrata group(C2) and Q. serrata-C obtusa group(C3). In tree layers importance value(IV) of C. japonica were 97.2% in C1, 80.7% in C2, and 47.6% in C3 and in sub-tree layers IV were 8.9% in C1, 15.2% in C2, and 5.7% in C3. Especially in C3 there are bamboo species (Smilacina japonica var. lutecarpa and Pseudosasa japonica) it is necessary for us to control them. In shrub layers C. japonica were found in C1(9.2%) and C2(7.0%), but except for C3. In tree layer species diversity indices of each community ranged from the lowest 0.059 in C1 to the highest 0.548 in C3. Dominance ranged from 0.958 in C1 to 0.393 in C3 which may caused by interspecific competition. Current annual increment of diameter growth ranged from 7.01mm/yr to 8.04mm/yr. As a result of our study we recommend the application of proper thinning and pruning for C1 and C2.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.6-22
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• 2022

In this paper classifies the types of 228 anchor stones discharged from the west and south coasts, assumes a combined method by type, routes through discharge locations, and It attempted to estimate the burial site. Prior to classification of types, the weight, thickness, width, and length of the anchor stone were measured, and the largest Young in the tomb The scent weight was classified into I~V groups, and the shape of the anchor stone was classified into 1-6 types. All of these weight and shape correlations It was classified into 17 types. The combined method by type is 180kg or less depending on the morphological characteristics of the reference value of the extracted anchor stone, and the type An anchor of type 1 or 2 is used in combination with an anchor, and a anchor of type 3 or 6 weighs more than 180kg and is combined with an anchor The dragon was assumed to be an anchor. Along with this, the route and burial site are identified through past records and testimony of local residents It was checked against the data. The route was largely consistent with past records, but the new route was apparent in waters near the island or inland It was also drawn. In the case of burial sites, small and large in Taean Mado Sea and Jindo Byeokpajin Sea, where anchor stones are concentrated, Considering the pattern of the type anchor stones being discharged, it was consistent with the testimony that ships of various sizes were mysterious in the two seas. Based on this type classification, a study on the spatiality of the anchors was conducted. First, a comparison and analysis was done on whether actual real data, such as anchor stones, old ships, and relics, were identified on the Joun-ro route and international trade routes as recorded in the past literature. Where there was no record, the route was estimated based on real data. To this end, routes estimated based on the testimony of local residents and modern ship workers were analyzed as to whether ships traveled there in the past and whether they could actually sail. Next, the location of each seedling was estimated by ship size according to the weight of the anchor stone. In the case of the Taean Mado Sea and Jindo Byeokpajin Sea, both small and large anchor stones were discharged from the coastline and were far away.

• Korean Journal of Ichthyology
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• v.35 no.2
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• pp.91-100
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• 2023

The early life history of Silurus microdorsalis living in Jahocheon Stream was studied by observing egg and morphological development. Live fish were captured in June 2018, then reared in a circulating filtration system under a 14L : 10D photoperiod with a water temperature of 18℃. To artificially induce spawning, females were injected with 0.5 mL of Ovaprim (Syndel, Nanaimo, BC, Canada) per kg of body weight, and males were injected with 10,000 IU/kg body weight of human chorionic gonadotropin. Approximately 15 h later, eggs were artificially inseminated by the dry method. Mature eggs were light pale yellow, which separated them from immature eggs. Fertilized eggs were 2.16±0.06 mm (n=8) in diameter and fully hatched at 181 h after fertilization. The fertilization rate was 63.1±2.2%, and 10.0±3.7% of the embryos were malformed at 18℃. The rates of development were 181 h at 18℃, 109 h at 21℃, and 76 h at 24℃. The larval size immediately after hatching was 4.64±0.22 mm (n=8), and the larvae displayed negative phototaxis at 1 day after hatching. The total larval length on 7 days after hatching was 12.47±0.53 mm, with 25~30 basal anal fin rays and 14~16 basal caudal fin rays observed. The total larval length was 14.13±0.51 mm on 9 days after hatching, and approximately 90% of the black endoplasmic reticulum was deposited on the head and body. The dorsal fin had formed, and a single basal body was observed. On 15 days after hatching, the total larval length was 16.69±0.31 mm; the number of basal caudal fin rays (18 poles) was an integer because 2 dorsal fin basal rays and 60~63 anal fin basal rays were observed. The total larval length was 28.96±1.10 mm on 50 days after hatching; the numbers of caudal fins (n=18), dorsal fins (n=3), pectoral fins (n=11), and anal fin basal rays (n=67~73) were integers.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.62-74
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• 2023

Much attention has been focused on the Baekpoman area due to the archaeological achievements of the past, but studies on prehistoric times when villages began to form is insufficient, and the Bronze Age village landscape was examined in order to supplement this. In the area of Baekpo Bay, the natural geographical limit connected to the inland was culturally confirmed by the distribution density of dolmens, and the generality of the Bronze Age settlement was confirmed with the Hwangsan-ri settlement. Bunto Village in Hwangsan-ri represents a farming-based village in the Baekpo Bay area, and the residential group and the tomb group are located on the same hill, and it is composed of three individual residential groups, and the village landscape had attached buildings used as warehouses and storage facilities. In the area of Baekpo Bay, it spread in the Tamjin River basin and the Yeongsan River basin where Songgukri culture and dolmen culture were integrated, and the density distribution of the villages was considered to correspond to the distribution density of dolmens. In order to examine the landscape of village distribution, the classification of Sochon-Jungchon-Daechon was applied, and it was classified as Sochon, a sub-unit constituting the village, in that the number of settlements constituting the village in the Bronze Age was mostly less than five. There are numerical differences between Jungchon and Daechon, and the distribution pattern does not necessarily coincide with the hierarchy. The three individual residential groups of Bunto Village in Hwangsan-ri are Jungchon composed of complex communities of blood relatives with each family community, and a stabilized village landscape was created in the Gusancheon area. In the area of Baekpo Bay, Bronze Age villages formed a landscape in which small villages were scattered around the rivers and formed a single-layered relationship. Dolmens (tombs) were formed between the villages and villages, and seem to have coexisted. Sochondeul is a family community based on agriculture, and it is believed that self-sufficient stabilized rural villages that live by acquiring various wild resources in rivers, mountains, and the sea formed a landscape.

• Journal of Environmental Impact Assessment
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• v.32 no.6
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• pp.450-462
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• 2023

This study suggested methodology of Citizen Science as a tool of ecosystem conservation and management to achieve Wetland Protected Area (WPA) Conservation Plan and examined whose applicability in 3 WPAs (Jangrok of Gwangju metropolitan city, Madongho of Goseong in South Gyeongsang Province, and Incheongang estuary of Gochang in North Jeolla Province). It consists of a) figuring out main interests and stakeholder or beneficiaries of WPA and their information demand based on conservation, utilization, and management target in the WPA Conservation Plan, b) conducting research activities to gain outcome to address stakeholder's demand, and c) returning the research outcome to citizen scientists and making diffusion to the society. Based on the suggested method and process, citizen scientists conducted ecosystem monitoring (plants including Invasive Alien Plants, terrestrial insects, traces of mammals, discovering unknown wetland). As a result, citizen scientists contributed to collecting species information of 16 plans, 43 species of terrestrial insects, 5 mammals including Lutra lutra (Endangered Species I) and Prionailurus bengalensis (Endangered Species II). The authors constructed and provided distribution map of Invasive Alien Plants, which included information of location and density which citizen scientists registered, for Environment Agencies and local governments who manage 3 WPAs to aid data-based ecosystem policy, In further studies, not only accumulating research data and outcomes acquired from citizen science to suffice the policy demands but also deliberate reviewing policy applicability and social·economic ripple effect should be processed for the suggested Citizen Science in WPA to be settled down as a tool of ecosystem conservation and management.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.174-193
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• 2023

Korea is surrounded by the sea and has rivers connecting to it throughout the inland areas, which has been a geographical characteristic since ancient times. As a result, there have been exchanges and conflicts with various countries through the sea, and rivers have facilitated the transportation of ships carrying grain, goods paid for by taxes, and passengers. Since the past, the sea and rivers have had a significant impact on the lives of Koreans. Consequently, it is expected that there are many cultural heritages submerged in the sea and rivers, and continuous efforts are being made to discover and preserve them. Underwater cultural heritage is difficult to discover due to its location in the sea or rivers, making direct visual observation and exploration challenging. To overcome these limitations, various geophysical survey techniques are employed. Geophysical survey methods utilize the physical properties of elastic waves, including their reflection and refraction, to conduct surveys such as bathymetry, underwater topography and strata. These techniques detect the physical characteristics of underwater objects and seafloor formation in the underwater environment, analyze differences, and identify underwater cultural heritage located on or buried in the seabed. Bathymetry uses an echo sounder, and an underwater topography survey uses a side-scan sonar to find underwater artifacts lying on or partially exposed to the seabed, and a marine shallow strata survey uses a sub-bottom profiler to find underwater heritages buried in the seabed. However, the underwater cultural heritage discovered in domestic waters thus far has largely been accidental findings by fishermen, divers, or octopus hunters. This study aims to analyze and summarize the latest research trends in equipment used for underwater cultural heritage exploration, including bathymetric surveys, underwater topography surveys and strata surveys. The goal is to contribute to research on underwater cultural heritage investigation in the domestic context.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.49-60
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• 2024

A region can be divided into cultivation zones based on homogeneity in weather variables that have the greatest influence on crop growth and yield. This study classified the cultivation zone of soybean using weather indices as a prior study to classify the agroclimatic zone of soybean. Meteorological factors affecting soybeans were determined through correlation analysis over a 10 year period (from 2013 to 2022) using data from the Miryang and Suwon regions collected from the soybean yield trial database of the Rural Development Administration, Korea and the meteorological database of the Korea Meteorological Administration. The correlation between growth characteristics and the minimum temperature, daily temperature range, and precipitation were high during the vegetative growth stages. Moreover, the correlation between yield components and the maximum temperature, daily temperature range, and precipitation were high during the reproductive growth stages. As a result of k-means clustering, soybean cultivation zones were divided into three zones. Zone 1 was the central inland region and southern Gyeonggi-do; Zone 2 was the southern part of the west coast, the southern part of the east coast, and the South Sea; and Zone 3 included parts of eastern Gyeonggi-do, Gangwon-do, and areas with high altitudes. Zone 1, which has a wide latitude range, was further subdivided into three cultivation zones. The results of this study may provide useful information for estimating agrometeorological characteristics and predicting the success of soybean cultivation in South Korea.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.505-518
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• 2023

The key to invasive pest management lies in preemptive action. However, most current research using species distribution models is conducted after an invasion has occurred. This study modeled the potential distribution of the globally notorious sweet potato pest, the sweet potato weevil(Cylas formicarius), that has not yet invaded Korea using MaxEnt. Using global occurrence data, bioclimatic variables, and topsoil characteristics, MaxEnt showed high explanatory power as both the training and test areas under the curve exceeded 0.9. Among the environmental variables used in this study, minimum temperature in the coldest month (BIO06), precipitation in the driest month (BIO14), mean diurnal range (BIO02), and bulk density (BDOD) were identified as key variables. The predicted global distribution showed high values in most countries where the species is currently present, with a significant potential invasion risk in most South American countries where C. formicarius is not yet present. In Korea, Jeju Island and the southwestern coasts of Jeollanam-do showed very high probabilities. The impact of climate change under shared socioeconomic pathway (SSP) scenarios indicated an expansion along coasts as climate change progresses. By applying the 10th percentile minimum training presence rule, the potential area of occurrence was estimated at 1,439 km² under current climate conditions and could expand up to 9,485 km² under the SSP585 scenario. However, the model predicted that an inland invasion would not be serious. The results of this study suggest a need to focus on the risk of invasion in islands and coastal areas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.270-284
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• 1997

Effects of dietary carotenoids were investigated on the metaboβsm and body pigmentation of rainbow trout(Salmo gairdneri), masu salmon(Oncorhynchus macrostomos), eel(Anguilla japonica), rock fish(Sebastes inermis) and black rock fish(Sebastes schlegeli). Three weeks later after depletion, these fishes were fed diet supplemented with ${\beta}-carotene$, lutein, canthaxanthin', astaxanthin or ${\beta}-apo-8'-carotenal$ for 4 to 5 weeks, respectively. Carotenoids distributed to and changed in integument were analyzed. In the integument of rainbow trout. zeaxanthin, ${\beta}-carotene$ and canthaxanthin were found to be the major carotenoids, while lutein, isocryptoxanthin and salmoxanthin were the minor carotenoids. In the integument of masu salmon, zeaxanthin was found to be the major carotenoids, while triol, lutein, tunaxanthin, ${\beta}-carotene$, ${\beta}-cryptoxanthin$ and canthaxanthin were the minor carotenoids. In the integument of eel, ${\beta}-carotene$ was found to be the major carotenoids, while lutein, zeaxanthin and ${\beta}-cryptoxanthin$ were the minor carotenoids. In the integument of rock fish, zeaxanthin, ${\beta}-carotene$, tunaxanthin$(A{\sim}C)$ and lutein were found to be the major carotenoids, while ${\beta}-cryptoxanthin$, ${\alpha}-cryptoxanthin$ and astaxanthin were the minor carotenoids. Likely in the integument of black rock fish, ${\beta}-carotene$, astaxanthin and zeaxanthin were found to be the major carotenoids, whereas ${\alpha}-cryptoxanthin$, ${\beta}-cryptoxanthin$, lutein and canthaxanthin were the minor contributor. The efficacy of body pigmentation by the accumulation of carotenoids in the integument of rainbow trout and masu salmon were the most effectively shown in the canthaxanthin group and of eel, rock fish and black rock fish were the most effectively shown in the lutein group. Based on these results in the integument of each fish, dietary carotenoids were presumably biotransformed via oxidative and reductive pathways. In the rainbow trout, ${\beta}-carotene$ was oxidized to astaxanthin via successively isocryptoxanthin, echinenone and canthaxanthin. Lutein was oxidized to canthaxanthin. Canthaxanthin was reduced to ${\beta}-carotene$ via isozeaxanthin, and astaxanthin was reduced to zeaxanthin via triol. In the masu salmon, ${\beta}-carotene$ was oxidized to zeaxanthin. Lutein was reduced to zeaxanthin via tunaxanthin. Canthaxanthin was reduced to zeaxanthin via ${\beta}-carotene$. and astaxanthin was reduced to zeaxanthin via triol. In the eel, ${\beta}-carotene$ and lutein were directly deposited but canthaxanthin was reduced to ${\beta}-carotene$, and cholesterol lowering effect by Meju supplementation might be resulted from the modulation of fecal axanthin, astaxanthin and ${\beta}-apo-8'-carotenal$ were oxidized and reduced to tunaxanthin via zeaxanthin. In the black roch fish, ${\beta}-carotene$ was oxidized to ${\beta}-cryptoxanthin$. Lutein was reduced to ${\beta}-carotene$ via ${\alpha}-cryptoxanthin$. Canthaxanthin was reduced to ${\alpha}-cryptoxanthin$ via successively ${\beta}-cryptoxanthin$ and zeaxanthin. Astaxanthin converted to tunaxanthin via isocryptoxanthin and zeaxanthin, and ${\beta}-apo-8'-carotenal$ was reduced to ${\alpha}-cryptoxanthin$ via ${\beta}-cryptoxanthin$ and zeaxanthin.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.243-255
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• 2014

This study was investigated to estimate the relations between benthic environments and benthic polychaetous community from April 2012 to February 2013. Twenty four stations were selected sequentially with Seomjin River Estuary from the northern part of Gwangyang Bay. The study area could be divided into three characteristic zones based on salinity, water temperature, dissolved oxygen and pH such as Saline Water Zone (SWZ), Brackish Water Zone (BWZ), and Fresh Water Zone (FWZ). Salinity was above 30.0 psu in SWZ, drastically decreased toward inland in BWZ, and nearly zero psu in FWZ. SWZ showed its specific environmental characters like that water temperature fluctuated with little seasonal change and DO showed the lowest values among three zones, and pH maintained as consistent value without seasonal fluctuation. In FWZ, on the other hand, water temperature showed high seasonal fluctuation, DO showed the highest values among three zones, and pH fluctuated greatly. In sedimentary environment, mud, sand and sand/gravel were found as dominant sedimentary deposits in SWZ, BWZ and FWZ, respectively. Organic matter content and AVS in surface sediment were high in SWZ, while Chl-a content high in FWZ. This study area showed a marked environmental difference between FWZ and SWZ as follows: FWZ has coarse sediment and low salinity, low organic matter content, low AVS in FWZ but SWZ has fine sediment and high salinity, high organic matter content and AVS. Species number and mean density of benthic polychaete community was highest in Saline Water Zone (SWZ), drastically decreased in Brackish Water Zone (BWZ), and lowest in Fresh Water Zone (FWZ). Dominant polychates above 5.0% of individual numbers were 6 taxa. Lumbrineris longifolia, Prionospio cirrifera, Tharyx sp. occurred as main dominant species of all study periods, and Hediste sp., Praxillella affinis, Tylorrhynchus sp. dominantly occurred at some seasons. Inhabiting areas of dominant species were separated characteristically. Representative species in SWZ were Lumbrineris longifolia, Tharyx sp., Mediomastus sp.. Wide-appearing species between SWZ and BWZ were Prionospio cirrifera, Heteromastus filiformis, Aricidea sp.. Characteristic species in FWZ were Tylorrhynchus sp. and Hediste sp.. As the results of cluster analysis and nMDS based on the species composition of polychaetous community, unique station groups were established in SWZ and FWZ. Stations in BWZ were sub-divided into several groups with season. Pearson's correlation analysis and PCA between benthic environments and ecological characteristics of polychaetous community showed that salinity, sediment composition, organic content and dissolved oxygen played a role to determine the temporal and spatial distribution of the ecological characteristics as species number, mean density, abundance of main species, and ecological indices.