• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.294-305
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• 1989

Basedon statistical data of pomfret (Pampus spp.) catches by the stow net during $1970\~1985$, the distribution and migration of pomfrets and fishing conditions were investigated in relation to oceanographic conditions, in the East China Sea and the Yellow Sea. The main fishing grounds of Pomfrets were formed around the Great Yangtze Sand Bank which locates between the Cheju Island and the mouth of the Yangtze River. Its area occupied only 11 percent of all fishing grounds, and about 70 percent of total catch was found there. The coefficient of variation(CV) in catch was below 0.01 in the whole fishing grounds and that of tile main fishing grounds (14 fishing areas) was $0.001\~0.003$. This area was indicated markedly by the inflow of Yellow Sea Warm Current from spring to autumn, and this mixing area which formed the oceanic front among the China Continental Shelf Water, the Yellow Sea Bottom Cold Water and the Tsushima Warm Current. The pomfrets migrates to south-north according to the expansion and contraction of the Tsushima Warm Current including the Yellow Sea Warm Current and the Yellow Sea Bottom Cold Water. Therefore, it migrates to north of the Yellow Sea in summer and to southern part of the East China Sea in winter. The most frequent range of the water type for high catch was $10\~12^{\circ}C$ in temperature and $32.4\~33.4\%_{circ}$ in salinity. The ranges was occupied more than 70 percent of total catch on fishing season. The frequency range of the water type was not different between the abundant fishing periods and the poor fishing periods in terms of the maximum catches.

• The KIPS Transactions:PartA
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• v.14A no.1 s.105
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• pp.47-54
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• 2007

In this paper we present a translation lookaside buffer (TLB) system with low power consumption for imbedded processors. The proposed TLB is constructed as multiple banks, each with an associated block buffer and a corresponding comparator. Either the block buffer or the main bank is selectively accessed on the basis of two bits in the block buffer (tag buffer). Dynamic power savings are achieved by reducing the number of entries accessed in parallel, as a result of using the tag buffer as a filtering mechanism. The performance overhead of the proposed TLB is negligible compared with other hierarchical TLB structures. For example, the two-cycle overhead of the proposed TLB is only about 1%, as compared with 5% overhead for a filter (micro)-TLB and 14% overhead for a same structure without continuos accessing distinction algorithm. We show that the average hit ratios of the block buffers and the main banks of the proposed TLB are 95% and 5% respectively. Dynamic power is reduced by about 95% with respect to with a fully associative TLB, 90% with respect to a filter-TLB, and 40% relative to a same structure without continuos accessing distinction algorithm.

• Journal of Marine Life Science
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• v.5 no.1
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• pp.1-8
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• 2020

This review is about current Streptococcosis of cultured olive flounder, Paralichthys olivaceus, in South Korea. The main bacterial species are Streptococcus iniae, S. parauberis and Lactococcus garvieae. The occurrence trend has been arranged with published data and seed bank (NIFS) data that was examined with deposited strains and the number from 2002 to 2017. S. iniae and L. garvieae were collected until 2012 and 2002, respectively, but not collected any more after that year. In recent years, the dominant strain of Streptococcosis of cultured olive flounder is S. parauberis. The phenotypic and genetic characteristics of standard strains and isolated strains were examined with published paper. Notably, we describe about distinguishing gross signs and histological signs of 3 types of Streptococcosis in this report. White turbidity of eye, hemorrhage, enteritis and ascites are main signs of S. iniae infection. Darkness of body surface, hemorrhage in somatic muscle and pericarditis are predominant in occasion S. parauberis infection. In occasion of L. garvieae infection, common signs of Streptococcosis are revealed, but these are weak tendency compared with the previous two cases.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.1
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• pp.1-15
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• 2017

This paper analyzes empirically how the three main industries (petrochemical industry, shipbuilding industry, automobile industry) that are driving the growth of Ulsan region in 2005~2013 have grown by what factors. For this purpose, we investigate the structural changes of the three main industries by using regional input-output tables announced by the Bank of Korea and examine the growth contribution rate of each industry that is divided into domestic final demand, export demand, import substitution for final goods, import substitution for intermediate goods and technological change, respectively. The growth rate of gross output and aggregate demand in petrochemical and automobile industries increased in 2010-1013 compared to 2005-2010, but the growth rate of gross output and aggregate demand in shipbuilding industry slowed down. As a result of analysis of factors contributing to the increase in gross output of the three main industries, export demand has the greatest effect. By industry, the rate of growth contribution of export demand in petrochemical industry is recorded as 209.23% in 2005-2010 and 113.78% in 2010-2013, respectively. The rate of growth contribution of export demand in automobile industry is recorded as 258.72% in 2005-2010 and 72.69% in 2010-2013, respectively. On the other hand, the rate of growth contribution of export demand in shipbuilding industry is recorded as 94.47% in 2005-2010, but it decreased to -255.32% in 2010-2013. Analysis of growth factors of Ulsan's three main industries is expected to serve as the basis for reorganizing related industrial policies and establishing them.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.333-343
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• 2012

In-stream large wood (LW) has a critical impact on the geomorphic characteristics relevant to ecosystem management and disaster prevention, yet relatively little is known about variations in its dynamics and subsequent export on the watershed-scale perspective in Korea. Here we review variations in the dynamics and subsequent export of LW as a function of stream size, which is appropriate for Korean mountain streams. In upstream channels with narrow bankfull widths and low stream discharges, a massive amount of LW, resulting from forest dynamics and hillslope processes, may persist for several decades on valley floor. These pieces, however, are eventually transported during infrequent debris flows from small tributaries, as well as peak hydrology in main-stem channels. During the transport, these pieces suffer fragmentation caused by frictions with boulders, and stream bank and bed. Although infrequent, these events can be dominant processes in the export of significant amounts of LW from upstream channel networks. In downstream channels with wide bankfull widths and high stream discharges, LW is dominantly recruited by forest dynamics and bank erosion only at locations where the channel is adjacent to mature riparian forests. With the LW pieces that are supplied from the upstream, these pieces are continuously transported downstream during rainfall events. This leads to further fragmentation of the LW pieces, which increases their transportability. With decreasing stream-bed slope, these floated LW pieces, however, can be stored and form logjams at various depositional sites, which were developed by interaction between channel forms and floodplains. These pieces may decay for decades and be subsequently transported as particulate or dissolved organic materials, resulting in the limitation of LW fluvial export from the systems. However, in Korea, such depositional sites were developed in the extremely limited streams with a large dimension and no flood history for decades, and thus it does not be expected that the reduction of LW export amount, which can be caused by the long-term storage. Our review presents a generalized view of LW processing and is relevant to ecosystem management and disaster prevention for Korean mountain streams.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.308-315
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• 1998

This study was conducted to evaluate the availability of the forest topsoil as a source of the "Native-soil(seed-fertilizer-soil materials)" for the hydroseeding measures which are environmentally and ecologically stable revegetation measures on rock cut-slopes. Soil sampling and factorial experiments were used with a split plot design(main plot : forest soil type and soil spraying thickness, subplot : seeding rate) in 1996. Results obtained in this study were summarized as follows : Because of the competition between the seeded(introduced) species and the native species, the number of naturally emerged species in the non-seeded plot and that of in the seeded plot were $5{\sim}9species/0.07m^2$ and $2{\sim}6species/0.07m^2$, respectively. As increasing the seeding rate(introduced species), the appearance ratio of naturally emerged species was decreased. The total number of individuals was high in the plot which used coniferous forest soil as a seed source, however the ratio of the individuals of naturally emerged species was high(30%) in the plot which used deciduous forest soil. The usage of the forest topsoil as seed bank source onto the "Native-soil" materials for hydroseeding could be reduce the seeding rate to $1,000seedlings/m^2$. According to the several factors which are competition between seeded species and naturally emerged species, dryness of soil materials, and seed burial, spraying thickness with more than 5cm was suitable for the growth of plants in variety.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.625-636
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• 2010

The geophysical characteristics and geological structure of the northeastern part of the Ulleung Basin were investigated from interpretation of geophysical data including gravity, magnetic, bathymetry data, and seismic data. Relative correction was applied to reduce errors between sets of gravity and magnetic data, obtained at different times and by different equipments. The northeastern margin of the Ulleung Basin is characterized by complicated morphology consisting of volcanic islands (Ulleungdo and Dokdo), the Dokdo seamounts, and a deep pathway (Korea Gap) with the maximum depth of -2500 m. Free-air anomalies generally reflect the topography effect. There are high anomalies over the volcanic islands and the Dokdo seamounts. Except local anomalous zones of volcanic edifices, the gradual increasing of the Bouguer anomalies from the Oki Bank toward the Ulleung Basin and the Korea Gap is related to higher mantle level and denser crust in the central of the Ulleung Basin. Complicated magnetic anomalies in the study area occur over volcanic islands and seamounts. The power spectrum analysis of the Bouguer anomalies indicates that the depth to the averaged Moho discontinuity is -16.1 km. The inversion of the Bouguer anomaly shows that the Moho depth under the Korea Gap is about -16~17 km and the Moho depths towards the Oki Bank and the northwestern part of Ulleung Island are gradually deeper. The inversion result suggests that the crust of the Ulleung Basin is thicker than normal oceanic crusts. The result of 20 gravity modeling is in good agreement with the results of the power spectrum analysis and the inversion of the Bouguer anomaly. Except the volcanic edifices, the main pattern of magnetization distribution shows lineation in NE-SW. The inversion results, the 2D gravity modeling, and the magnetization distribution support possible NE-SW spreading of the Ulleung Basin proposed by other papers.

• 한국해양학회지
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• v.25 no.4
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• pp.205-216
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• 1990

This study was carried out to investigate the composition and the distribution of the polychaete community in Kwangyang Bay during 1987-1988, and to deduce causal factors of temporal changes in community by the comparison with the results of 1982 (Choi, 1984). In the present study, the Polychaetes comprised a total of 79 species, and had a mean density of 520 ind. $.$m/SUP -2/. They showed high abundance and species diversity in the main tidal channel and the north channel of Myodo. The most abundant polychaete was Lumbrineris longifolia (28.2%), and followed by Nephtys polybranchia (16.3%) and Stermaspis scutata (8.3%). Comparing the polychaete community in summer of 1987 with that in summer of 1982, Lagis bocki and Chone teres, the most dominant species in 1982, disappeared in 1987, while Lumbrineris longifolia, Nephtys polybranchia, Terebellides horikoshii, and Sternapis scutata experienced above twice increases in densities. the community in the north channel was distinguished from those in other regions by the high abundance of L. bocki in 1982, but was similar to that of the main channel by the disappearance of L. bocki in 1987. The community in the western inner bay was similar to that of the main channel in 1982, but became to be distinguished by the disappearance of l. longifolia and the high densities of S. scutata and Tharyx sp. in 1987. The temporal change in species composition and regional difference might be induced by the combined effects in the changes of hydrologic and sedimentary environments owing to the reclamation on the delta of Seomjing River and the dredging of the north chnnel.L.bocki in the north chnnel vanished after the habitat disturbance by the reclamation and dredging.S.scutata and Tharyxsp.dominated in the western inner bay because of the accumulationfo fine sediments through weakenend durrent flow by the obstruction of a new bank constructed on the delta.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.143-159
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• 2024

Natural aggregate is an essential resource for human activities, closely related to construction. The aggregate demand has been increasing annually, and due to the nature of the resource, it is difficult to procure from distant locations. This study identifies the distribution and characteristics of aggregate-bearing areas as part of a municipal-level aggregate resource survey conducted in Nonsan City, Korea, in 2023. Nonsan City is located approximately 35 km straight distance from the Geum River estuary and lies at the passageway of the main stream of the Geum River. The topography of Nonsan City features eastern mountainous areas and western plains, creating an east-high-west-low geomorphic setting, with 33 streams distributed across the city, including tributaries of the Geum River like Nonsan Stream, Noseong Stream, and Ganggyeong Stream. All streams originate from the highlands in the north and east, converge with Nonsan Stream, and then join the west bank of the main stream of the Geum River at the western boundary of Nonsan City. Drilling core results show shallow depths in the highlands to the north and east, deepening towards the west, reaching a maximum depth of 25 m near the main stream of the Geum River. The total reserve of land aggregates is calculated to be 246,789,000 m³, with a developable amount of 172,750,000 m³. The total reserve of river aggregates is 5,236,000 m³, with a developable amount of 3,765,000 m³. The distribution of aggregates varies according to the geomorphic, geologic, and development pattern of the river system. Reserves are scarce in mountainous areas but are abundant in regions with rivers and wide alluvial plains, although reserves appear at depths greater than 4m. The distribution of aggregate resources in Nonsan City is influenced by stream activities and sea level changes, with the tidal range of the Yellow Sea acting as an unfavorable condition for the preservation of aggregate resources.

• The Korean Journal of Applied Statistics
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• v.23 no.1
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• pp.63-71
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• 2010

Business entrepreneurs reflect their views of domestic and foreign economic activities on their operation for the growth of their business. The decision, forecasting, and planning based on their economic sentiment affect business operation such as production, investment, and hiring and consequently affect condition of national economy. Business survey index(BSI) is compiled to get the information of business entrepreneurs' economic sentiment for the analysis of business condition. BSI has been used as an important variable in the short-term forecasting models for business cycle analysis, especially during the the period of extreme business fluctuations. Recent financial crisis has arised extreme business fluctuations similar to those caused by currency crisis at the end of 1997, and brought back the importance of BSI as a variable for the economic forecasting. In this paper, the meaning of BSI as an economic sentiment index is reviewed and a GUIDE regression tree is constructed to find out the factors which affect on BSI. The result shows that the variables related to the stability of financial market such as kospi index(Korea composite stock price index) and exchange rate as well as manufacturing operation ratio and consumer goods sales are main factors which affect business entrepreneurs' economic sentiment.