Application of probabilistic neural network to design breakwater armor blocks     

Dookie Kim  Dong Hyawn Kim  Seongkyu Chang 《Ocean Engineering》2008,35(3-4):294-300

This study presents a probabilistic neural network (PNN) technique for predicting the stability number of armor blocks of breakwaters. The PNN is prepared using the experimental data of Van der Meer. The predicted stability numbers of the PNN are compared with those of previous studies, i.e. by an empirical formula and a previous neural network model. The agreement index between the measured and predicted stability numbers by PNN are better than those by the previous studies. The PNN offers a way to interpret the network's structure in the form of a probability density function and it is easy to implement. Therefore, it can be an effective tool for designers of rubble mound breakwaters.  相似文献   

Coastal environmental assessment and management by ecological simulation in Yeoja Bay, Korea     

Dae-In Lee  Jeong-Min Choi  Yeon-Gyu Lee  Moon-Ock Lee  Won-Chan Lee  Jong-Kyu Kim   《Estuarine, Coastal and Shelf Science》2008,80(4):495-508

An eco-hydrodynamic model was used to estimate the carrying capacity of pollutant loads and response of water quality to environmental change in Yeoja Bay, Korea. An energy-system model also was used to simulate the fluctuation in nutrients and organic matter in the bordering wetland. Most water quality factors showed a pulsed pattern, and the concentrations of nutrients and organic matter of seawater increased when input loads of nutrients increased due to freshwater discharge. The well-developed tidal zones and wetlands in the northern area of the bay were highly sensitive to input loads. Residence times of water, chemical oxygen demand (COD), and dissolved inorganic nitrogen (DIN) within the bay were estimated to be about 16 days, 43.2 days, and 50.2 days, respectively. Water quality reacted more sensitively to the effects of nitrogen and phosphorus input than to COD. A plan to reduce the present levels of COD and dissolved inorganic phosphorus (DIP) by 20–30% and DIN by at least 50% in pollutant loads is needed for satisfying the target water quality criteria. The natural removal rate of nutrients in wetlands by reeds was assessed to be approximately 10%.  相似文献   

Radium tracing of submarine groundwater discharge (SGD) and associated nutrient fluxes in a highly-permeable bed coastal zone, Korea   总被引：2，自引：0，他引：2  

Guebuem Kim  Jae-Woong Ryu  Dong-Woon Hwang 《Marine Chemistry》2008,109(3-4):307

In order to estimate submarine groundwater discharge (SGD) and SGD-driven nutrient fluxes, we measured the concentrations of nutrients, ²²⁴Ra, and ²²⁶Ra in seawater, river water, and coastal groundwater of Yeongil Bay (in the southeastern coast of Korea) in August 2004 and February 2005. The bottom sediments over the shallow areas of this bay are composed mainly of coarse sands. Large excess concentrations of ²²⁴Ra, ²²⁶Ra, and Si supplied from SGD were observed in August 2004, while these excess concentrations were not apparent in February 2005. Based on the mass balance for ²²⁴Ra, ²²⁶Ra, and Si, which showed conservative mixing behavior in seawater, SGD was estimated to be approximately 6 × 10⁶ m³ day^− 1 (seepage rate = 0.2 m day^− 1) in shallow areas (< 9 m water depth) in August 2004, which is much higher than the SGD level typically found in other coastal regions worldwide. During the summer period, SGD-driven nutrients in this bay contributed approximately 98%, 12%, and 76% of the total inputs for dissolved inorganic nitrogen (DIN), phosphorus (DIP), and silicate (DSi), respectively. Our study implies that the ecosystem in this highly permeable bed coastal zone is influenced strongly by SGD during summer, while such influences are negligible in winter.  相似文献   

Compliance costs and the small fisher: A study of exiters from the New Zealand fishery     

James Stewart  Kim Walshe 《Marine Policy》2008

Over 3000 predominantly small-scale fishers have exited the New Zealand's quota management system (QMS) between its inception in 1986 and 2000. This study, based on the Ministry of Fisheries database and a questionnaire sent to the exiters, establishes that compliance costs in general, and those specifically related to the QMS, were one of the most consistent reasons for exit. Uncertainty about future QMS policy and the high cost of quota were also significant factors. It appears that the small fishers’ perception of high compliance cost can be supported by industry data.  相似文献   

Review of recent findings on the water masses and circulation in the East Sea (Sea of Japan)   总被引：1，自引：0，他引：1  

Kuh Kim  Kyung-Il Chang  Dong-Jin Kang  Young Ho Kim  Jae-Hak Lee 《Journal of Oceanography》2008,64(5):721-735

Recent findings on water masses, biogeochemical tracers, deep currents and basin-scale circulation in the East/Japan Sea, and numerical modeling of its circulation are reviewed. Warming continues up to 2007 despite an episode of bottom water formation in the winter of 2000–2001. Water masses have definitely changed since the 1970s and further changes are expected due to the continuation of warming. Accumulation of current data in deep waters of the East/Japan Sea reveals that the circulation in the East/Japan Sea is primarily cyclonic with sub-basin scale cyclonic and anticyclonic cells in the Ulleung Basin (Tsushima Basin). Our understanding of the circulation of intermediate water masses has been deepened through high-resolution numerical studies, and the implementation of data assimilation has had initial success. However, the East/Japan Sea is unique in terms of the fine vertical structures of physical and biogeochemical properties of cold water mass measured at the highest precision and their rapid change with the global warming, so that full understanding of the structures and their change requires in-depth process studies with continuous monitoring programs.  相似文献   

Fostering Environmental Sensitivity by Observing Everyday Environments     

Minsung Kim 《The Journal of geography》2019,118(4):157-168

This study examined the effects of observing and reflecting on everyday environments in the development of environmental sensitivity, defined as a holistic capability composed of predisposition, knowledge, and behavior subdimensions. We encouraged participants to use diverse sources, such as texts, photographs, and animation, to record their observations and thinking. As a result, the activity in this study was beneficial in enhancing students’ environmental sensitivity. Students’ mean scores on the environmental sensitivity questionnaire improved, and their reflective journals reported increased interest in everyday environments, enhanced knowledge about diverse environmental elements, and strengthened will to act pro-environmentally. The usefulness of the geospatial platform was also reported.  相似文献   

A study of coral reef resilience and implications of adaptive management and rehabilitation in Khanh Hoa Province, Vietnam     

VO Si Tuan  HUA Thai Tuyen  PHAN Kim Hoang 《海洋学报(英文版)》2019,38(1):112-117

The Province of Khanh Hoa, Vietnam, is located in the western South China Sea and boasts a shoreline of 385 km and many islands. Previous studies have indicated the extreme diversity and abundance of coral reefs in its waters as compared with other coastal provinces of Vietnam. A study on the resilience of coral reefs against increased surface water temperature and anthropogenic impact is conducted at 19 reef sites in 2015. At each site, a series of parameters (e.g., coral covers, genus diversity, and coral recruitment, substratum heterogeneity, depth, water exchange level, and sediment deposit and water temperature) are measured quantitatively or semi-quantitatively. The measured data are rated based on the relationship between the parameter values and coral susceptibility; the consideration that reef health reflects the biological capability to adapt to environmental changes and the recruitment potential if bleached; and positive or negative influences of physical factors in the mitigation of thermal stress and protecting corals from bleaching. A cumulative analysis enables researchers to divide the studied reefs into four categories based on varying levels of reef health to support resilience, recovery, and vulnerability in the case of increased water temperature. Relevant management interventions for each category and other supporting activities are suggested to enhance management effectiveness and to plan the rehabilitation of coral reefs for biodiversity conservation and touristic development, taking into account the involvement of related stakeholders.  相似文献   

Molecular Identification and Expression Analysis of Carbonic Anhydrase VII in Pufferfish (Takifugu rubripes)     

Sumi  Kanij Rukshana  Kim  Soo Cheol  Howlader  Jewel  Sharker  Md Rajib  Choi  Kap Seong  Choi  Sang Ki  Park  Jong-In  Nou  Ill-Sup  Kho  Kang Hee 《Ocean Science Journal》2019,54(3):363-374

Ocean Science Journal - A carbonic anhydrase VII gene, encoding 277 amino acids, was identified in the intestinal tissue of pufferfish (Takifugu rubripes). The translated protein with an 833-bp...  相似文献   

Temperature-Dependent Bifurcated Seasonal Shift of Phytoplankton Community Composition in the Coastal Water off Southwestern Korea     

Kang  Yoonja  Kang  Hee-Yoon  Kim  Dongyoung  Lee  Young-Jae  Kim  Tae-Ik  Kang  Chang-Keun 《Ocean Science Journal》2019,54(3):467-486

Ocean Science Journal - Coastal water around the archipelago off southwestern Korea has been bathed in an unprecedented pool of warm water in summer in recent years. Here, we examined phytoplankton...  相似文献   

A Review on Marine N2 Fixation: Mechanism,Evolution of Methodologies,Rates, and Future Concerns     

Bhavya  P. S.  Min  Jun-Oh  Kim  Min-Seob  Jang  Hyo Keun  Kim  Kwanwoo  Kang  Jae Joong  Lee  Jae Hyung  Lee  Dabin  Jo  Naeun  Kim  Myung Joon  Kim  Yejin  Lee  Junbeom  Lee  Chang Hwa  Bae  Hyeonji  Yoo  Hyeju  Park  Sanghoon  Yun  Mi Sun  Lee  Sang Heon 《Ocean Science Journal》2019,54(4):515-528

Ocean Science Journal - Investigations on marine N2 fixation have gained momentum since 1960s with eventual establishments of relevant methodologies to identify species involved and quantify the...  相似文献