• Journal of the Korean GEO-environmental Society
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• v.12 no.6
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• pp.25-34
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• 2011

Dredged and reclaimed ground in progress at the West Coast has a high content of coarse particles. There will be different behaviors depending on the location of outlet and engineering properties of soil when its ground is dredged by a pump. Therefore, the experiments were conducted that were manufactured about the chamber equipment of length 2,650mm, width 770mm, height 735mm, experimented step filling method and water content about 300%, 500% and 700% respectively with SM and ML samples in order to realize segregating sediment characteristics of dredged ground with changing much fine. With results of analysis, ML sample by higher initial water content was reached to the period of complete sedimentation and coefficient of sedimentation consolidation increased with increases of diffusion distance. SM samples showed behavior of coarse soil with diffusion distance 120cm, diffusion distance of more than 120cm showed a similar tendency with ML sample under the influence of fines. In ML sample, it could be also found that lower depth and the more increasing diffusion distance increase in percentage of sieve #200 but water content decreases. In SM sample, it could be also found that coarse soil was piled at near the diffusion distance zone but fine soil was piled at the far diffusion distance zone and prominent difference showed between percentage of sieve #200 and water content(%) by boundary point 120cm~160cm of both samples. Also, shear strength was expressed ML-maximum 2.97kPa, SM-maximum 10.2kPa with diffusion distance.

• Journal of Cadastre & Land InformatiX
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• v.51 no.1
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• pp.23-38
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• 2021

In this paper, we analyzed the possibility of utilizing LX-PPS GNSS permanent stations whose antennas are installed on the building rooftop for the purpose of high-precision GNSS positioning services. We picked 15 pairs of adjacent GNSS permanent stations operated by LX-PPS and NGII, and then produced 3-year-long time series using the high-precision data processing software called GIPSY. Patterns and trends of position estimates were compared and analyzed. Horizontal and vertical deviations including the linear velocities coincide with the well-known crustal deformation rates of the Korean peninsula. We also observed almost the same annual or seasonal patterns from those nearby sites. After detrending the linear velocity, the amplitude and phase of annual signals almost perfectly match each other within the baseline length of 2 km. By subtracting seasonal signals, the RMS and standard deviations in LX-PPS PPGR with respect to NGII KANR are about 1, 2, and 5 mm in the north-south, east-west, and vertical directions, respectively. From this analysis it can be concluded that the rooftop-installed LX-PPS sites show similar level of stability and positioning performance comparable to those ground-mounted NGII stations.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.1
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• pp.26-39
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• 2021

This study investigated the characteristics of the watershed and pollutants in the Seonakdong River basin in the lower stream of the Nakdong River Water System, and evaluated the areas vulnerable to nonpoint pollution by subwatershed according to the TOPSIS(Technique for Order of Preference by Similarity to Ideal Solution) method. The selection method consists of selection of evaluation factors, calculation of weights and selection of areas vulnerable to non-point pollution through evaluation factors and weights. The entropy method was used as the weight calculation method and TOPSIS, a multi-criteria decision making(MCDM) method was used as the evaluation method. Indicator data were collected as of 2018, and national pollution source survey data and national statistics were used. Most of the vulnerable watersheds were highly urbanized had a large number of residents and were evaluated as having a large land area among industrial facilities and site area rate. Through this study, it is necessary to approach a variety of weighting methodologies to assess the vulnerability of non-point pollution with high reliability, and scientific analysis of the factors that affect non-point pollution sources and consideration of the effects are necessary.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.1
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• pp.5-13
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• 2022

Sunbigi tree(Vitex rotundifolia L.f.), which grows wild in the southern part of Korea and along the coast of the West Sea, has a lot of useful value in terms of resource utilization. Since ancient times, it has been used as folk medicine or herbal medicine in the private sector. Although the leaves and stems have a strong scent, the fruit also has a strong scent, so there are some studies on extracting essential oil from the fruit of Sunbigi tree and analyzing the ingredients, but there are few studies on the fragrance component by extracting hydrosol. The reason is that the fruits are hard and it is difficult to identify the active ingredients contained in the general extraction method. Therefore, in this study, the results of analyzing the components contained in the fragrance of hydrosol obtained by extracting hard fruits at high temperature by different extraction methods are as follows. 1. The extraction condition with the highest flavonoid content was 30.57 mg/g with ethanol, followed by hot water extract at 18.26 mg/g and water extract at 9.69 mg/g with the lowest. 2. As a result of distillation extraction from the fruit of Sunbigi tree, the fragrance of hydrosol is 3-Methyl-2-butenoic acid, cyclobutyl ester, Eucalyptol, L-alpha-Terpineol, 1H-Cycloprop[e]azulen-7-ol, decahydro-1 ,1,7-trimethyl-4-methylene-, [1ar-(1a.alpha.,4a.alpha.,7.beta.,7a.beta.,7b.alpha.)] were found to be many.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.295-307
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• 2021

The Korean Peninsula is surrounded on three sides by the East Sea, West Sea and South Sea which are connected to many rivers and streams, thereby facilitating easy inflow of debris from land. Furthermore, excessive debris inflow to the sea because of active fishing and various recreational activities. Debris entering the sea are weighted over time and settle in the seabed, thus, making direct monitoring of debris impossible and its collection difficult. Uncollected submerged marine debris affects the seabed ecosystem and water quality and can cause ghost fishing and ship accidents, especially due to waste net ropes and waste fishing gears. Therefore, understanding the debris distribution characteristics is necessary to assist quick collection of these debris (waste net ropes and waste fishing gears). Thus, this study conducted a survey of debris deposited in the seas of 39 ports. Furthermore, distribution characteristics and compositions of submerged marine debris were identified by a map prepared through GIS-based spatial analysis of the East Sea. Consequently, 58% of waste tires in the East Sea were concentrated in breakwaters and ship berthing facilities. Moreover, 26 % of waste plastics were distributed outside the port. Identifying the distinct distribution characteristics of submerged marine debris was difficult; however, compared with others, the distribution of waste plastics was possible outside the port. The findings of this study can serve as baseline data to assist the collection of submerged marine debris using the distribution characteristics.

• The Korea Journal of Herbology
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• v.28 no.1
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• pp.23-31
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• 2013

Objectives : The purpose of this study was to determine the anti-obesity effect and molecular mechanism of YY312, a herbal extract composed of Imperatae Rhizoma, Citri Unshius Pericarpium Immaturus, and Evodiae Fructus, on a high-fat diet-induced animal model and on 3T3-L1 cells. Methods : C57BL/6 mice were fed for 6 weeks with a normal diet or a high-fat diet (HFD). Then they orally administered daily with 300 mg/kg YY312 for next 10 weeks. Body weight and food consumption were recorded weekly and daily, respectively. Tissue weights, serum lipid, and glucose levels were analyzed at the end of the study. Additionally, the effects of YY312 on adipocyte differentiation in 3T3-L1 cells were examined. After differentiating 3T3-L1 cells were treated with YY312, Oil-red O staining, RT-PCR, and Western blotting were performed for lipid accumulation, mRNA expression of adipogenesis gene, and AMP-activated protein kinase (AMPK) phosphorylation, respectively. Results : YY312-administered mice showed a significant reduction of body weights and abdominal adipose tissue weights. YY312 also reduced the serum levels of triglycerides and total cholesterol, compared with the HFD group. Treatment with YY312 inhibited lipid accumulation and blocked expression of adipogenic transcription factors and lipogenesis genes, including peroxisome proliferator-activated receptor ${\gamma}$, CCAT/enhancer binding protein ${\alpha}$ and fatty acid synthase. YY312 increased AMPK phosphorylation in 3T3-L1 adipocytes. Conclusions : This study showed that herbal extract YY312 has an anti-obesity effect in vitro and in vivo. Thus, YY312 could be developed as a supplement for reduction of body weight gain induced by an HFD.

• Korean Journal of Ichthyology
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• v.34 no.2
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• pp.73-85
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• 2022

The cynoglossid fishes are popular for food in the world including Korea, China and Japan, and among them, Paraplagusia japonica lives all over the sea of Korea. In order to establish appropriate management measure, it is essential to clarify population structure of P. japonica from the morphological and molecular perspectives. We collected a total of 132 individuals of P. japonica from six localities in Korea between 2008 and 2021. Canonical discriminant analysis results showed that the West Sea population (Incheon) slightly differed from the South (Tongyeong, Busan) and East Sea populations (Pohang, Donghae, Sokcho). Similar results were also shown in Kruskal-Wallis test of meristic characters. Furthermore, neighbor-joining and maximum-likelihood trees based on 849 base pairs of mitochondrial DNA cytochrome b sequences showed that P. japonica was divided into two lineages (designated as A and B) with a high significance (Φ_st=0.0781, P<0.001). Interestingly, however, the two lineages in the admixture area (South-East Sea) were not different in morphological characters. Our results suggest that P. japonica had undergone differentiated history during the Late Pleistocene, but secondary contact may occur at the admixture area.

• Maritime Security
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• v.4 no.1
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• pp.83-113
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• 2022

Although China's maritime militia has not been well known despite its long history, it is recently emerging as a serious threat to maritime security, causing neighboring countries' security concerns due to the growing number of maritime disputes with China. In this regard, it is now time to clearly define the true nature of the Chinese maritime militia. A close look at the organization and roles of the Chinese maritime militia reveals that it is an organization that is systematically managed and operated by the Chinese government and the People's Liberation Army of China. Its role is to serve the purpose of "contributing to the protection and expansion of China's marine interests." In addition, the threat factors of the Chinese maritime militia were analyzed by examining the cases of maritime disputes between the Chinese maritime militia and neighboring countries. First, the Chinese maritime militia has implemented the "Gray Zone Strategy." Second, it is a systematic organization supported by the Chinese government and the People's Liberation Army. Third, it is a maritime power that cannot be ignored as the world's largest militia organization. Fourth, it has a strategic flexibility that enables the execution of the dual mission of working for a living such as commercial fishing and serving in the maritime militia. The threats of the Chinese maritime militia are not limited to Southeast Asian countries located in the South China Sea. This is also the case in Korea as the country cannot avoid maritime disputes with China such as the Ieodo issue and the boundary delimitation of the West Sea. Accordingly, this study was focused on presenting a predictable scenario and countermeasures based on the analysis through a scenario technique with respect to the two cases that are most likely to occur in Korea-China relations. Finally, beyond identifying the nature of the Chinese maritime militia, this study takes a further step to share considerations as to how the organization may operate and develop in the future and how we can cope with its moves.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.138-145
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• 1988

The effect of directions (north to south vs east to west) of planting row, planting intensities (10/15, 15/15, 20/15, 25/15 cm/cm) and the number of rows consecutively (1,2, 3,4) for both the CMS and pollen parent in alternation, on the seed yield of CMS of rice was tested with a breeding line V20A/Iri342$\^$*8/. When the planting row was made in vertical direction to the wind direction during anthesis, the seed yield was higher than the other direction regardless the planting densities and number of rows consecutive. Seed yield increased as high as 46.9%. The higher planting intensities up to 10/15 cm/cm yielded the higher hybrid seeds. The highest yield was 81.2 kg/ha. The yield variation among plants within a plot and among the plants within a replication was relatively large. Increased pollen parent row numbers caused increased grain fertility per plant, but the seed yield was increased by reduced pollen parent row number. Reduced CMS parental row numbers caused increased grain fertility per plant, but the seed yield was increased by increased CMS parental row numbers. Considering the hybrid seed yield, parental seed yield and operational convenience, 4 rows of CMS and 1 row of pollen parent in alternate with 20/15 or 25/15 (cm/cm) planting densities seemed to be the rational layout.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.462-469
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• 2023

In this study, we propose a method for evaluating the risk of collision between ships to support determination on the risk of collision in a situation in which ships encounter each other and to prevent collision accidents. Because several uncertainties are involved in the navigation of a ship, must be considered when evaluating the risk of collision. We apply the Dempster-Shafer theory to manage this uncertainty and evaluate the collision risk of each target vessel in real time. The distance at the closest point approach (DCPA), time to the closest point approach (TCPA), distance from another vessel, relative bearing, and velocity ratio are used as evaluation factors for ship collision risk. The basic probability assignments (BPAs) calculated by membership functions for each evaluation factor are fused through the combination rule of the Dempster-Shafer theory. As a result of the experiment using automatic identification system (AIS) data collected in situations where ships actually encounter each other, the suitability of evaluation was verified. By evaluating the risk of collision in real time in encounter situations between ships, collision accidents caused by human errora can be prevented. This is expected to be used for vessel traffic service systems and collision avoidance systems for autonomous ships.