• Structural Engineering and Mechanics
• /
• v.53 no.3
• /
• pp.481-495
• /
• 2015

Many hydropower stations in southwest China are located in regions of brittle rock mass with high geo-stresses. Under these conditions deep fractured zones often occur in the sidewalls of the underground caverns of a power station. The theory and methods of fracture and damage mechanics are therefore adopted to study the phenomena. First a flexibility matrix is developed to describe initial geometric imperfections of a jointed rock mass. This model takes into account the area and orientation of the fractured surfaces of multiple joint sets, as well as spacing and density of joints. Using the assumption of the equivalent strain principle, a damage constitutive model is established based on the brittle fracture criterion. In addition the theory of fracture mechanics is applied to analyze the occurrence of secondary cracks during a cavern excavation. The failure criterion, for rock bridge coalescence and the damage evolution equation, has been derived and a new sub-program integrated into the FLAC-3D software. The model has then been applied to the stability analysis of an underground cavern group of a hydropower station in Sichuan province, China. The results of this method are compared with those obtained by using a conventional elasto-plastic model and splitting depth calculated by the splitting failure criterion proposed in a previous study. The results are also compared with the depth of the relaxation and fracture zone in the surrounding rock measured by field monitoring. The distribution of the splitting zone obtained both by the proposed model and by the field monitoring measurements are consistent to the validity of the theory developed herein.

• Journal of Korean Society for Atmospheric Environment
• /
• v.9 no.4
• /
• pp.329-339
• /
• 1993

Due to the global-convection currents, transboundary transport of air pollutants is widely observed in many regions of the world. This study was carried out to investigate the pattern of long-range transport of air pollutants in North East Asia, especially the impact of air pollutants originated in China and Japan on the air quality in Korea. From the meteorological data at the 850 mb surface from May 1986 through April 1987 at 54 obsevation stations in the North East Asia region, the backward and forward trajectories were calculated using interpolation method. And the contributions of pollution sources in neighbor countries to the air quality in Korea were analyzed. It was concluded that air pollution in China had a great influence on the air quality in Korea throughout the year : it could be transported to Korea just within 2 or 3 days most of the time. The trajectory analysis showed that pollution sources in Beijing. Liaoning Province, and Shandong Province, the most heavily industrialized areas in China., were the most influential for the air quality in Korea except for summer season. Durnig summer season, the air pollution in Shanhai and Japan could have moer influence on Korea. Such transboundary transport of air pollutants necessitate international cowork and cooperation in the region of North East Asia.

• Corrosion Science and Technology
• /
• v.17 no.1
• /
• pp.6-11
• /
• 2018

Outdoor exposure tests using of 7B04 aluminium alloy samples including plate, tensile and various SCC samples were carried out in Tuandao station, Shandong province (East of China) and Wanning station, Hainan province (South of China). Corrosion characteristics including weight loss, microstructure, tensile strength and SCC susceptibility were investigated. The corrosion rates in Tuandao and Wanning showed high to low and the corrosion rates changed to the following equation of $w=at^b$ (b<1). The corrosion of 7B04 aluminium alloy in Wanning was more serious than that in Tuandao. Pitting appeared at early stage of expose test, and it can be changed to general corrosion with test time extension. The 7B04 aluminium alloy of which specimen shapes are forging and thick plate also showed SCC (Stress corrosion cracking) in the marine atmosphere. The higher SCC sensitivity was observed in Wanning station than in Tuandao station. The 7B04 aluminium alloy with a high stress level was more sensitive to SCC. Intergranular and transgranular or a mixed mode of cracking can be observed in different marine exposure.

• International journal of advanced smart convergence
• /
• v.10 no.2
• /
• pp.158-167
• /
• 2021

Fishery industry is an important part of agricultural industry in coastal countries. The purpose of this study is to use the theory of industrial competitiveness for reference, use Analytic Hierarchy Process (AHP) and Delphi method to establish the evaluation index system, and analyze the fishery industry competitiveness of 11 coastal provinces in China. This study data came from China Fishery Statistical Yearbook 2020. The results show that Shandong Province is the most competitive province in fishery industry among the coastal provinces. The inter-provincial differences are great. Not only the resource endowment is the factor that affects the fishery industry competitiveness, but also the long-term profitability is too. The proportion of recreational fishery in the fishery economic output value has become one of the main indicators to measure the competitiveness of the fishery industry. The findings of this study suggest that all regions should adopt measures in accordance with local conditions, promote the integrated development of the fishery industry, enhance the added value of fishery products and enhance the competitiveness of fishery industry. The disadvantage of this study is that the fishery industry competitiveness of China's coastal provinces is only compared and analyzed. The future direction is to carry out a comparative study on the international competitiveness of fishery with other east Asian countries.

• Journal of Ocean Engineering and Technology
• /
• v.23 no.6
• /
• pp.1-6
• /
• 2009

An Overtopping Wave Energy Convertor (OWEC) is an offshore wave energy convertor used for collecting overtopping waves and converting the water pressure head into electric power through hydro turbines installed in a vertical duct affixed to the sea bed. A numerical wave tank based on the commercial computational fluid dynamics code Fluent is established for the corresponding analysis. The Reynolds Averaged Navier-Stokes equation and two-phase VOF model are utilized to generate the 2D numerical linear propagating waves, which are validated by the overtopping experiment results. Calculations are made for several incident wave conditions and shape parameters for the overtopping device. Both the incident wave periods and heights have evident effects on the overtopping performance of the OWEC device. The computational analysis demonstrates that the present overtopping device is more compatible with longer incident wave periods.

• The Journal of Fisheries Business Administration
• /
• v.24 no.2
• /
• pp.83-97
• /
• 1993

Since the last decade, the fisheries industry in Korea has faced many difficulties in terms of comparative economic advantage partly because of marine environmental damage caused by Pollution and coastal reclamation, and partly because of too expensive production factors like labor. In addition, new order of world trade created by Uruguay Round will force the Korean fisheries industry to prepare some remedies including a joint-venture business with China for international compatativeness. As a result, this paper mainly deals with an analysis on feasibility of Sino-Korean joint cooperation in fisheries business. Especially, the Shandong Province in China is expected to take advantage of its geographical proximity to Koreas well as of its abundance in marine natural resources in order to achieve a fast economic growth. Thus, for the next decade to come, it would be very important for the Korean fisheries industry to cope with the international fisheries market by the Sino-Korean joint-venture combining the capital and technology from Korea with the cheap labor and favorable marine environment for aquaculture from China.

• International Area Studies Review
• /
• v.14 no.2
• /
• pp.159-180
• /
• 2010

The purpose of this study is to examine how perceived service quality, value congruence influences uncertainty avoidance, customer satisfaction and customer loyalty, and in turn, provides insight for Korean banks when they penetrate into the Chinese marketplace. In so doing, this study conducts a survey on participants who are using banking services in the Changchun, Jinan, Guangzhou of Jilin Province, Shandong Province and Guangdong Province. The findings are as followed. First, Uncertainty avoidance plays an important mediating role in the relationship between perceived service quality and customer satisfaction, between value congruence and customer satisfaction. Uncertainty avoidance has a direct effect on customer satisfaction, but is significantly negative. Second, value congruence has a direct effect on uncertainty avoidance, but is significantly negative. Third, customer satisfaction has a direct effect on attitudinal loyalty and behavioral loyalty.

• Atmosphere
• /
• v.27 no.4
• /
• pp.455-466
• /
• 2017

In Korea, property and human damages occur annually due to heavy precipitation during the summer. On August 8, 2015, heavy rainfall occurred in the Seoul metropolitan area due to an outflow boundary, and $77mmhr^{-1}$ rainfall was recorded in Gwangju, Gyeonggi Province. In this study, the simulation of the WRF numerical model is performed to understand the cause and characteristics of heavy rainfall using the Conditional Instability of the Second Kind (CISK), potential vorticity (PV), frontogenesis function, and convective available potential energy (CAPE) analyses, etc. Convective cells initiated over the Shandong Peninsula and located on the downwind side of an upper level trough. Large amounts of water vapor were supplied to the Shandong Peninsula along the southwestern edge of a high pressure system, and from the remnants of typhoon Soudelor. The mesoscale convective system (MCS) developed through CISK process and moved over to the Yellow Sea. The outflow boundary from the MCS progressed east and pushed cold pool eastward. The warm and humid air over the Korean Peninsula further enhanced convective development. As a result, a new MCS developed rapidly over land. Because of the latent heat release due to convection and precipitation, strong potential vorticity was generated in the lower atmosphere. The rapid development of MCS and the heavy rainfall occurred in an area where the CAPE value was greater than $1300Jkg^{-1}$ and the fronto-genesis function value of 1.5 or greater coincided. The analysis result shows that the MCS driven by an outflow boundary can be identified using CISK process.

• Geomechanics and Engineering
• /
• v.11 no.3
• /
• pp.345-359
• /
• 2016

In order to investigate the influence of the interfacial angel on failure characteristics and mechanism of combined coal-rock mass, 35 uniaxial/biaxial compressive simulation tests with 5 different interfacial angels of combined coal-rock samples were conducted by PFC2D software. The following conclusions are drawn: (1) The compressive strength and cohesion decrease with the increase of interfacial angle, which is defined as the angle between structure plane and the exterior normal of maximum principal plane, while the changes of elastic modulus and internal friction angle are not obvious; (2) The impact energy index $K_E$ decreases with the increase of interfacial angle, and the slip failure of the interface can be predicted based on whether the number of acoustic emission (AE) hits has multiple peaks or not; (3) There are four typical failure patterns for combined coal-rock samples including I (V-shaped shear failure of coal), II (single-fracture shear failure of coal), III (shear failure of rock and coal), and IV (slip rupture of interface); and (4) A positive correlation between interfacial angle and interface effect is shown obviously, and the interfacial angle can be divided into weak-influencing scope ($0-15^{\circ}$), moderate-influencing scope ($15-45^{\circ}$), and strong-influencing scope (> $45^{\circ}$), respectively. However, the confining pressure has a certain constraint effect on the interface effect.

• Journal of Korea Trade
• /
• v.26 no.1
• /
• pp.20-32
• /
• 2022

Purpose - This paper intends to make theoretical analysis and empirical test on the factors influencing China's export to South Korea, and draw conclusions about China's export efficiency and trade potential. Based on the conclusions, the reasons for China's trade deficit with South Korea are found, and a solution is put forward for solving the problem of China's trade deficit with South Korea. Design/methodology - Based on the data of 2004-2017 years in China, this paper uses the stochastic frontier gravity model to analyze the influencing factors of China's export to South Korea, as well as the export efficiency of each province and the export potential that can be explored. Findings - First, in terms of the factors affecting China's export trade to South Korea, the GDP of the provinces and cities in China, the FDI of South Korea to the provinces and cities in China, the GDP of South Korea, the population and education level of provinces and cities in China can significantly promote the export scale of Chinese provinces and cities to South Korea. The distance between Chinese provincial capitals and the South Korean capital significantly hinders Chinese exports to South Korea; Second, in terms of export trade efficiency, the trade exchange rate of the economically developed cities along the eastern coast of China and several provinces that are close to South Korea is higher than that of the cities in the central and western regions; Third, economic globalization makes trade more convenient, the average export trade efficiency of China's exports to South Korea showed an upward trend. However, under the influence of the 2008 global financial crisis, the export trade efficiency declined from 2008 to 2009, indicating that the impact of the financial crisis on the trade efficiency cannot be ignored. Originality/value - This paper finds out the influencing factors of China's export to South Korea, analyzes the export efficiency of different provinces and cities, excavates the export potential, and puts forward some suggestions for the balanced development of China and South Korea trade in the next step.