• Title/Summary/Keyword: dominant period

Search Result 1,136, Processing Time 0.029 seconds

A Critical Review on the Critical Communication Studies in Korea (한국의 비판언론학에 대한 비판적 성찰: 문화연구와 정치경제학을 중심으로)

  • Cho, Hang-Je
    • Korean journal of communication and information
    • /
    • v.43
    • /
    • pp.7-46
    • /
    • 2008
  • The purpose of this essay explores a critical review of the Korean critical communication studies focused on the problematic of cultural studies and political economy in 2000s. The findings are as follows; The 'consumer turn' or 'audience turn' in new revisionism modelling John Fiske's cultural studies has been interpreted not to complement but to substitute the necessary criticism of the post-authoritarian media establishment of Korea at that time, arising identity crisis of Korean cultural studies as one of the critical camp. On other side, however, some political economy studies close to the unilinear theses of orthodox marxism has been appraised to neglect the complex process and structure of media and cultural production as well. While the press war between the market-dominant dailies and some progressive dailies has given rise to a whole debate as expected in consolidating period of Korean emerging democracy, the conjucturalism as modelled by Hall's 'authoritarian populism' failed to initiate a new theo tical practice in Korea. Finally, this review essay propose the some new research issues that would converge cultural studies and political economy, modernism and postmodernism; citizenship vs 'cultural citizenship'(valuing the private identity and gender) or Habermasian public sphere vs 'cultural public sphere', the culture of production, (modern)citizen/(postmodern)consumer(recently debated in English media policy), 'differentiation' in capitalist production and 'difference' in consumer sovereignty, 21c future vision of public service broadcasting as one of the 20c institutions.

  • PDF

Column Tests for the Design of PRB System using CFW (음식폐기물 탄화재로 충진된 PRB설계법 제안을 위한 컬럼실험)

  • Han, Jung-Geun;Yoon, Won-Il;Jung, Dong-Ho;Kim, Yong-Soo;Lee, Jong-Young
    • Journal of the Korean Geosynthetics Society
    • /
    • v.10 no.2
    • /
    • pp.35-43
    • /
    • 2011
  • Permeable Reactive Barriers (PRB) method is an economical method that does not require any other methods to be operated once it is installed as it controls of groundwater flow in the barrier, which is inserted a reactive material on the way of pollutant. The major dominant element of PRB is a reactive material in the reactive wall, and such factors as purification efficiency and used time based on the chemical and physical features in between the reactant and pollutant. High purification efficiency can be expected when a rational design that is synthetically considered in features of packing density, operation period, and adsorption reactant of pollutant. A column test was conducted for an application test using CFW as its adsorption reactant in order to remove copper($Cu^{2+}$) in the PRB system. The CFW was used for the reactant and selected inflow speed, density and thickness of PRB as its necessary factors for design of PRB. As a result of the experiment, the removal efficiency decreased as operating time of PRB increased and the efficiency linearly increased upon the length. Therefore, it is confirmed that the thickness of reactive materials in PRB system can be designed using the proposed formula considering purification time and density of CFW.

Characteristic of Fish Community and Distribution of Exotic Species at the Hangang River in Seoul, Korea (서울시 한강의 어류군집과 외래종 분포 특성)

  • Byeon, Hwa-Keun
    • Korean Journal of Ichthyology
    • /
    • v.30 no.3
    • /
    • pp.144-154
    • /
    • 2018
  • This study investigated the characteristics of fish communities at the Hangang River in Seoul from Jun 2016 to March 2017. During the survey period, there were 56 species of 17 families collected from 5 survey stations. The species that appeared mainly in the brackish water was Coilia nasus, Leiocassis nitidus, Lateolabrax maculata, Repomucenus olidus, Trachidermus fasciatus, Mugil cephalus, Chelon haematocheilus, Synechogobius hastus, Tridentiger bifasciatus and Takifugu obscurus. The migration fish of Anguilla japonica, C. nasus, Plecoglossus altivelis, Hypomesus nipponensis and T. obscurus appeared in this surveyed area. Korean endemic species were 11 species (17.9%) and accounted for a low rate. There were 6 species (10.7%) exotic species including Cyprinus carpio, Carassius cuvieri, Hypophthalmichthys molitrix, Megalobrama amblycephala, Lepomis macrochirus and Micropterus salmoides. The dominant species by stations were Acheilognathus gracilis (St. 1) and Hemibarbus labeo (St. 2, 3, 4, 5). Regarding the tolerance guild according to water quality, there were 3 (7.1%) sensitive species, 24 (42.9%) intermediate species, and 28 (50.0%) tolerance species. Twenty (35.7%) were insectivore species, 18 (32.1%) were omnivore species, 14 (25.0%) were carnivore species, and 4 (7.1%) were herbivore species, indicating the dominating presence of insectivore and omnivore fish species.

Characteristics of Summer Rainfall over East Asia as Observed by TRMM PR (TRMM 위성의 강수레이더에서 관측된 동아시아 여름 강수의 특성)

  • Seo, Eun-Kyoung
    • Journal of the Korean earth science society
    • /
    • v.32 no.1
    • /
    • pp.33-45
    • /
    • 2011
  • The characteristics and vertical structure of the rainfall are examined in terms of rain types using TRMM (Tropical Rainfall Measuring Mission) PR (Precipitation Radar) data during the JJA period of 2002-2006 over three different regions; midlatitude region around the Korean Peninsula (EA1), subtropical East Asia (EA2), and tropical East Asia (EA3). The convective rain fraction in the EA1 region is 12.2%, which is smaller by 6% than those in the EA2 and EA3 regions. EA1 shows less frequent convective rain events, which are about 0.5 times as many as those in EA3. EA1 produces the mean convective rain rate of 10.4 mm/h that is about 40% larger than EA2 and EA3 while all regions have similar mean stratiform rain rate. The relationships between storm height and rain rate indicate that the rain rate is proportional to the storm height. Based on the vertical structure of radar reflectivity, EA1 produces deeper and stronger convective clouds with higher rain rate compared to the other regions. In EA3, radar reflectivity increases distinctly toward the land surface at altitude below 5 km, indicating more dominant coalescence-collision processes than the other regions. Furthermore, the bright band of stratiform rain clouds in EA3 is very distinct. In convective rain clouds, the first EOFs of radar reflectivity profiles are similar among the three regions, while the second EOFs are slightly different. The larger variability exists at upper layers for EA1 while it exits at lower levels for EA3.

Variations of Sediment Textural Parameters and Topography around Gangneung Harbor after the Completion of Harbor Construction (강릉항 완공 후 주변해역의 퇴적물 조직변수와 지형의 변화)

  • Oh, Jae-Kyung;Bang, Ki-Young
    • Journal of the Korean earth science society
    • /
    • v.34 no.2
    • /
    • pp.120-135
    • /
    • 2013
  • To investigate the changes in depositional environment around Gangneung Harbor, we analyzed the surface sediment textural parameters and topography data collected five times from February 2007 to February 2009. In the study area, sediments were mainly composed of sand and its sediment size became finer at offshore sites. During summer time, however, the sand grains became coarser than winter season near Namhangjin Beach, inside the harbor, and offshore areas. On the other hand, the grain size of Anmok Beach showed a gradual finer trend with time. Compared with the previous studies conducted before the completion of Gangneung Harbor construction, the mean grain size became finer on Anmok Beach, while it was coarser on Namhangjin Beach. The bathymetric changes observed over a 2-year period showed predominant erosion in the area of 5 to 10 m water depths and deposition in 2 to 5 m water depths. The shallower area less than 2 m water depths showed an alternating trend and yet slightly more dominant erosion process. The sediment textural parameters and the distribution of erosion and deposition have changed continuously. Results imply that such changes show long-term trends as well as seasonal variations in which the trend may have been formed after the completion of Gangneung Harbor construction.

Growth Characteristics, Bio-chemical Composition and Antioxidant Activities of Benthic Diatom Grammatophora marina from Jeju Coast, Korea

  • Affan, Abu;Karawita, Rohan;Jeon, Yu-Jin;Kim, Bo-Young;Lee, Joon-Baek
    • ALGAE
    • /
    • v.21 no.1
    • /
    • pp.141-148
    • /
    • 2006
  • Benthic diatoms are known as a good food for shellfish in nature and in commercial hatchery of Jeju Island, Korea. Grammatophora marina is commonly found as dominant benthic micro-algae in Jeju coastal waters throughout the year. To know the best growth conditions of this species, culture was done in terms of three parameters; water temperature, salinity and nutrients. Each parameter was controlled by temperature of 15, 20 and 25°C; salinity of 25, 30 and 35 psu; and nutrient concentrations of 50, 100 and 200%. F/2 media was used with artificial seawater for the culture, which was continued for two weeks with L:D cycle 12:12 by using fluorescent light. Maximum specific growth rate was recorded 1.68 d–1 at temperature of 25°C with salinity of 35 psu and nutrient concentration of 200% on 6th day during the culture period. Maximum biomass was also observed 4.9 × 105 cells mL–1 in the same condition. This species may belong to the euryhaline and eutrophic habitat with warm condition. For nutritional aspects of this species, protein, lipid and carbohydrate were measured. The value of protein, lipid and carbohydrate was 4.96%, 15.82% and 5.65%, respectively. The antioxidant activities of 80% methanolic extract were 46.7%, 23.7% and 23.8% on DPPH (1,1-Diphenyl-2-picrylydrazy) radical, superoxide anion radical and hydrogen peroxide scavenging, respectively. Percentage metal chelating activity was 81.2%. Enzymatic extracts of Alcalase and Ultraflow showed remarkable scavenging activities on DPPH radical (86.5% and 57.2%, respectively), and superoxide anion scavenging activities were 45.3% and 41.4% from Kojizyme and Viscozyme extracts, respectively. Extract of Protomex revealed 24.8% activity on hydrogen peroxide and Neutase showed 30.8% on hydroxyl radical scavenging effects. Celluclast and Viscozyme extracts showed 33.2% and 32.1% activities on nitric oxide scavenging, respectively, while Alcalase showed 61.5% on metal chelating. This species contains higher lipids among the biochemical compounds and higher metal chelating activities from both 80% methanolic and enzymatic extracts.

Spatial Variation in Macrobenthic Communities Affected by the Thermal Discharge Volumes of a Nuclear Power Plant on the East Coast of Korea (원자력 발전소의 온배수 배출량 변화에 따른 대형저서동물 군집의 공간 변화)

  • Yu, Ok Hwan;Lee, Hyung-Gon;Lee, Jae-Hac;Kim, Kyung-Tae;Myung, Cheol-Soo;Moon, Hyung Tae;Byun, Ju Young
    • Ocean and Polar Research
    • /
    • v.35 no.4
    • /
    • pp.299-312
    • /
    • 2013
  • This study analyzed the species composition and density of a macrobenthic community according to variations in the thermal discharge volumes of a nuclear power plant before, during, and after the shutdown of the nuclear power plant during two periods. In this study, 369 macrobenthic fauna species were collected, and their mean density was 1,712 ind. $m^{-2}$. The number of species and diversity of macrobenthic fauna decreased with distance from the thermal discharge area, regardless of whether the nuclear plant shutdown or not. Many macrobenthic taxa appeared near the thermal discharge area, but polychaetes species were more prominent in outer areas than at the discharge area. The density of macrobenthic fauna decreased with distance from the thermal discharge area during a plant shutdown in the fall of 2011, but increased, except at two sites, near the discharge area in the winter of 2012. Cluster analysis indicated that the spatial distribution of the macrobenthic community changed in areas near the nuclear power plant after a shutdown period; that is, the station group I, in areas near the nuclear power plant, became narrower after the shutdown, but it recovered to previously occupied areas after the nuclear power plant began operating again. Opportunistic species, such as the polychaetes Lumbrineris longifolia (= Scoletoma longifolia) and Mediomastus californiensis, which were present in high densities near thermal discharge areas, decreased after the shutdown but recovered after the plant re-opened. The number of species and diversity of the macrofauna and the density of dominant species showed a significant correlation with temperature, except in winter periods. The results of this study revealed that changes in the amount of thermal discharge before and after the shutdown of a nuclear power plant could exert an influence on the structure of macrobenthic community within the thermal discharge areas depending on the season.

Analysis of Flavor Components of Coffee Beans in Polyethylene and Polypropylene Packaging Materials during Storage (원두커피 향미 성분의 폴리에틸렌과 폴리프로필렌 포장재에서의 저장 차이 분석)

  • Yu, Ha Kyoung;Lee, Seung Uk;Oh, Jae Young
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
    • /
    • v.23 no.2
    • /
    • pp.89-95
    • /
    • 2017
  • Although the global coffee market is growing every year and the demand for coffee wrapping paper is increasing accordingly, research on the effect of PE material and PP material on the coffee aroma used in the sealant layer, which will directly contact the product, is lacking. In this study, we studied the change of aroma patterns and flavor materials by adding coffee to PP and PE pouches. In addition, we observed changes in aroma patterns depending on the temperature and the presence of the deoxidizer. As a result, it was found that the PP type packaging material was slightly better than the PE type packaging material, but the performance was hardly changed by the material. Rather, the change in the aroma pattern due to temperature was dominant rather than the material. It is ideal that refrigerated distribution ($4^{\circ}C$) is the best storage temperature and sales are done within a short period of time. Among the indicators, pyridine was the most suitable material to study and there are many data about pyridine. Therefore, it is expected that the results can be derived by using pyridine.

Temporal and Spatial Changes in the Species Composition and Abundance of Benthic Polychaetes after the Construction of Shihwa Dike (West Coast of Korea) (시화 방조제 건설 이후 시화호 다모류의 종 조성 몇 서식밀도 변화)

  • Ryu, Jong-Seong;Choi, Jin-Woo;Kang, Seong-Gil;Koh, Chul-Hwan;Huh, Sung-Hoi
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.2 no.2
    • /
    • pp.101-109
    • /
    • 1997
  • The present study was carried out to investigate the temporal and spatial changes in species composition and abundance of polychaetes in Lake Shihwa. Macrobenthic fauna were collected from eight sampling surveys performed in March, June, September and December of 1994, March and October of 1995, February and August of 1996, using a modified van Veen grab with 0.1 $m^2$ coverage area. Polychaete worms, the most abundant macrofaunal group, comprised of 1~22 species at each investigation; number of species continuously decreased during the survey period. The mean density of polychaete was $794{\pm}1,275\;indiv.{\cdot}m^{-2}$ and showed a large fluctuation over time. The variation in abundance was mainly coupled with the domination of Polydora ligni occupying 83% in total density. The next dominant species were Pseudopolydora kempi (mean density of 31 $indiv.{\cdot}m^{-2}$) and Capitella capitata (mean density of 23 $indiv.{\cdot}m^{-2}$). Abundant polychaetes in Lake Shihwa are known to be tolerant to sediment pollution. Ecological indices such as diversity (H') and dominance (D) also indicated that the number of species significantly decreased and a few species predominated in Lake Shihwa after the dike construction. The azoic zone were extended from the upper reach of Lake Shihwa to the vicinity of the dike over time. The reduced number of species, predominance of pollution indicator species and development of an azoic zone reflect severe deterioration of benthic environments in Lake Shihwa.

  • PDF

Diel Changes of Cyanobacterial Toxins in Outflow Water of Lake Suwa (Suwa호 방류수내 남조류 독소(microcystin)의 일변화)

  • Kim, Bom-Chul;Park, Ho-Dong;Katagami, Yukimi;Hwang, Soon-Jin;Kim, Ho-Sub
    • Korean Journal of Ecology and Environment
    • /
    • v.34 no.3 s.95
    • /
    • pp.175-184
    • /
    • 2001
  • The temporal and diel changes of cyanobacterial cell density, species composition, and cyanobacterial toxins (microcystin-RR, -YR, -LR) were examined for the outflow water of Lake Suwa in Japan from May to October, 1998. The highest total cell densities of Microcystis were observed in July and September, when the dominant phytoplankton was Microcystis ichthyoblabe and M. viridis, respectively. Both the species composition and total cell density of Microcystis affected the variation of the concentration of three microcystin variants. Only microcystin-RR(MC-RR) and -LR (MC-LR) were detected in July when Microcystis ichthyoblabe dominated, while microcystin-RR, -YR (MC-YR) and -LR were detected in August and October when Microcystis viridis dominated. The microcystin concentration and the cell density of Microcystis in the outflow water showed diel variations; the ratio of maximum to minimum value was $3{\sim}20$ fold far microcystin concentration, and $5{\sim}31$ fold for cell density. The diel variations of toxin concentration as well as Microcystis cell density was closely related to the diel variation of wind. During the windy period, when higher speeds occurred in the afternoon hours than morning hours, both the cell density of Microcystis and microcystin concentration tended to increase in the morning and decrease in the afternoon. The results of this study suggest that controlling the timing of lake discharge at the floodgate or intake tower can be useful for water resource management with respect to decreasing cyanobacteria biomass within intake water.

  • PDF