A fifty-year production and economic assessment of common property-based management of marine living common resources: A case study for the women divers communities in Jeju,South Korea     

Jae-Young Ko  Glenn A. Jones  Moon-Soo Heo  Young-Su Kang  Sang-Hyuck Kang 《Marine Policy》2010

We examined the conditions of successful common property-based management for coastal marine living resources, using a case of historically and anthropologically well established women divers communities on Jeju Island, South Korea, focusing on their decentralized work rules and production records. Due to their tight social network and work rule, the women divers have harvested coastal marine living resources with limited fishing pressure exclusively from their village fishing grounds for over 400 years. However, their harvest patterns have been mostly reactive to market prices, eventually requiring direct governmental regulations such as total allowable catch in some cases. Most recently, the communities have been experiencing multiple challenges: their aging population, water pollution in the coastal zone, competition with cultured products and imported seafood, and expanding barren grounds. These challenges demand a multi-scale/dimensional response if the women divers communities are to keep their village fishing grounds and communities sustainable.  相似文献   

Temporal dynamics,meteorological effects,secondary organic aerosol estimation,and source identification of size-segregated carbonaceous aerosols     

Burçak Tarhan  Ebru Koçak 《洁净——土壤、空气、水》2024,52(4):2300095

During the period 2019–2020, size-segregated aerosol samples containing elemental and organic carbon (EC and OC) were investigated. These samples were collected weekly using an eight-stage cascade impactor from an urban site located at Aksaray University, Aksaray. The quantification of EC and OC was carried out through a thermal-optical transmission device. The results revealed consistent size distribution attributes of EC and OC between winter and summer. Although EC accounted for an insignificant percentage (4.4%) of particulate matter (PM) in the PM_9.0–10.0 fraction during winter, a more substantial portion of OC in the same fraction (13.4%) comprised EC. Seasonal variations were distinct for EC but not significant for OC. Strong correlations between OC and EC were observed in coarse particle fractions, indicating a common source, with weaker correlations in fine particles. The highest OC/EC ratio was in the PM_0.43–0.65 fraction, followed by PM_2.1–3.3. The ratio of OC to EC in fine PM exceeded the threshold of 15 consistently. The observation indicates that as particle size increases, there is a noticeable decline in the OC to EC ratios. Secondary organic aerosols (SOA) accounted for 60.8% (winter) and 89.8% (summer) of OC values, emphasizing the substantial impact of SOA on Aksaray's atmosphere. Both seasons exhibited a multimodal distribution of ambient OC. In winter, the EC distribution was dominated by fine particles, with a bimodal pattern (PM_1.1–2.1 and PM_0.43–0.65 peaks). Common pollutant sources, including traffic emissions, road dust, biogenic emissions, and coal combustion, were identified for both seasons in coarse and fine particle fractions. These findings underscore the importance of emission control strategies targeting fine PM in Aksaray.  相似文献   

Experimental developments for studying static and seismic behavior of retaining walls with liquefiable backfills     

M. M. Dewoolkar  H. -Y. Ko  R. Y. S. Pak 《Soil Dynamics and Earthquake Engineering》2000,19(8):75-593

The effects of earthquakes on cantilever retaining walls with liquefiable backfills were studied. The experimental techniques utilized in this study are discussed here. A series of centrifuge tests was conducted on aluminum, fixed-base, cantilever wall models retaining saturated, cohesionless backfills. Accelerations on the walls and in the backfill, static and excess pore pressures in the soil, and deflections and bending strains in the wall were measured. In addition, direct measurements of static and dynamic lateral earth pressures were made. In some tests, sand backfills were saturated with the substitute pore fluid metolose. Modeling of model type experiments were conducted. The experimental measurements were found internally consistent and repeatable. Both static and dynamic earth pressure measurements were determined to be reliable. It was also observed that for the test configuration adopted, a special boundary treatment such as the use of duxseal is optional. Static and seismic modeling of models were also successful, which indicated that the assumed scaling relations were essentially correct.  相似文献   

Palaeomagnetism of the quaternary sediments of the locality Červený Kopec (red hill)     

Alois Kočí  Reviewer P. Pagáč 《Studia Geophysica et Geodaetica》1973,17(3):232-239

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Comparison of different systems of deflections of the vertical in the Czechoslovakian test area     

Miloš Pick  Ivana Jakubcová  Milada Kožíšková 《Studia Geophysica et Geodaetica》1970,14(2):186-190

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Phase transformation studies on a synthetic hedenbergite up to 26 GPa at 1200° C     

Y.-H. Kim  L. C. Ming  M. H. Manghnani  J. Ko 《Physics and Chemistry of Minerals》1991,17(6):540-544

Phase transformations in a synthetic hedenbergite (CaFeSi₂O₆) have been observed with X-ray diffraction up to 26 GPa at 1200° C in a diamond anvil cell with a YAG laser heating system. Hedenbergite first decomposes into spinel, stishovite, and cubic perovskite phases at 16 GPa, and spinel further decomposes into wüstite and stishovite at 19 GPa. Between 19 GPa and 26 GPa, the phase assemblage is wüstite + stishovite+ perovskite. On decompression to 0.1 MPa, all the highpressure phases are retained except the cubic perovskite, which reverts to a retrogressive phase of CaSiO₃. A comparison of the results of this study with those from a previous study on a natural hedenbergite suggests that the garnet phase formed from natural hedenbergite is stabilized by manganese.  相似文献   

Relationship between mn nodule abundance and other geological factors in the northeastern pacific: Application of gis and probability method     

Youngtak Ko  Saro Lee  Jonguk Kim  Ki-Hyune Kim  Mee-Sook Jung 《Ocean Science Journal》2006,41(3):149-161

The aims of this study are 1) to construct a database using geostatistics and Geographic Information System (GIS), and 2) to derive the spatial relationships between manganese nodule abundance and other geological factors such as metal grade, slope, water depth, topography, and acoustic characteristics of the sub-bottom. Using GIS, it is possible to analyze a large amount of data efficiently, and to maximize the practical application, to increase specialization, and to enhance the accuracy of the analyses. The greater the copper and nickel grade, the higher the rating. The distribution pattern of nickel grade is similar to that of copper grade. The slopes are generally less than 3° except for seamounts and cliff areas. The rating shows no correlation with slope. The rating is highest for slopes between 2.5 and 3.5° in block N1 and between 4.0 and 4.5° in block N3. The topography is classified into five groups: seamount, hill crest, hill slant, hill base or plain, and seafloor basin or valley. The rating proves lowest for seamount and hill crest. Our results show that the rating increases with the water depth in the study area. Nodule abundance dose not show any significant relationship with the thickness of the upper transparent layer in the study area.  相似文献   

Internal recycling of particle reactive organic chemicals in the Chesapeake Bay water column     

Fung-Chi Ko  Lawrence P. Sanford  Joel E. Baker 《Marine Chemistry》2003,81(3-4):163-176

Hydrophobic organic contaminants (HOCs) may be used as tracers of particle dynamics in aquatic systems. Internal cycling of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were studied in the mesohaline Chesapeake Bay to assess the role of resuspension in maintaining particle and contaminant inventories in the water column, and to compare settling and suspended particle characteristics. Direct measurements of sediment resuspension and settling conducted in conjunction with one of the sediment trap deployments indicate reasonable agreement between measurements of particle flux using the two different methods. Organic carbon and PCB concentrations in settling solids collected in near-surface sediment traps were remarkably lower than concentrations in suspended particles collected by filtration during the trap deployments, but higher PAH concentrations were found in the settling particles. The different behaviors of PAHs and PCBs in the settling particles are due to their different source types and association to different types of particles. Sediment trap collections in near bottom waters were dominated by resuspension. Resuspension fluxes of HOCs measured 2 m above the bay bottom were as high as 2.5 μg/m² day for total PCBs and 15 μg/m² day for fluoranthene, and were 25 and 10 times higher than their settling fluxes from surface waters, respectively. HOC concentrations in the near bottom traps varied much less between trap deployments than HOC concentrations in the surface traps, indicating that the chemical composition of the resuspended particles collected in the near bottom traps was more time-averaged by repeated resuspension than the surface particles.  相似文献   

Active tuned liquid column damper with propellers     

Yung‐Hsiang Chen  Chia‐Hao Ko 《地震工程与结构动力学》2003,32(10):1627-1638

The active control of a Tuned Liquid Column Damper (TLCD) with two propellers is presented. A single‐degree‐of‐freedom system with a passive or active TLCD is used as an example to set up the basic equation of motion. The Optimal Control Theory is applied to establish the control law and to calculate the control force generated by these two propellers installed inside the TLCD. A simple pendulum‐like model test is carried out to study the dynamic characteristics of the passive and active TLCDs and the effectiveness of the vibrational control. Comparison of the experimental result with the analytical one shows a good agreement. Finally, the analytical results of the seismic response are also included as an example for demonstration and application. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Prototype LAAS Architecture Design Considerations     

Boris S. Pervan  Samuel P. Pullen  David G. Lawrence  Konstantin Gromov  Jock Christie  Guttorm Opshaug  Vicky Lu  Ping-Ya Ko  Per Enge  Bradford W. Parkinson 《GPS Solutions》1998,2(1):49-61

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