• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.35-42
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• 2017

Process Hazard Analysis(PHA) have been performed for a risk management of process (petrochemical) industry for nearly 50 years. There are many PHA methods for application in the process industry, Hazop Study method has been recognized as a good method used typically in most of phase of process plant. And also there was inconvenient opinion that Hazop Study is too resource (man power, time etc.) consuming comparing its result performance (a quality of recommendations) for a good operating and existing plant. In this study, two types of PHA method - checklist and K-PSR - were performed respectively for a new para-xylene(PX)plant and 30 year old PX plant. Past history and experience of incident, operation, maintenance and so on are very important in PHA by those two methods. The higher effectiveness were realized in PHA by a checklist and K-PSR Method than prior Hazop study. And also some suggestions including PHA cycle determination, RBPS application, Follow-up plan of PHA result etc. were proposed about PHA improvement measures for a best risk management.

• Korean journal of food and cookery science
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• v.31 no.6
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• pp.733-740
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• 2015

This study was performed to examine the functional and quality characteristics of rice cookies with added Ligularia fischeri (Ledeb.) Turcz. powder. Rice cookies were prepared with different amounts (0%, 0.5%, 1%, 1.5% and 2% to the flour quantity) of Ligularia fischeri powder. The antioxidant activities of Ligularia fischeri powder, specifically the total phenolic content, DPPH free radical scavenging activity and reducing power were found to be 212.19 mg GAE/g, $11.78{\mu}g/mL$11.78 ($IC_{50}$), and 2.33 (O.D.), respectively. The antioxidant activities of the rice cookies with added Ligularia fischeri powder increased with increasing concentrations of Ligularia fischeri powder. Regarding the hunter's color value of rice cookies with added Ligularia fischeri powder, L (lightness) and a (redness) values decreased (p<0.001) with increasing concentrations of Ligularia fischeri powder, whereas b (yellowness) values increased (p<0.01). The consumer acceptability score for the 3% Ligularia fischeri rice cookie groups ranked significantly (p<0.001) higher than the other groups in color, flavor, taste, texture and overall preference. These results suggest that Ligularia fischeri powder will be useful as a functional food resource with antioxidant activities.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.535-538
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• 2004

Coordination between supply chain partners is viewed critical to effective supply chain management. Depending on the bargaining power balance between them, it is determined who will be able to exert more influence in making decisions related with such coordination. We consider two cases of the decision-making structure in the context of a simple supply chain consisting of two players, i.e., (1) the first case in which a supply chain partner dominates the decision-making process and the other passively follows the dominant player's decision, and (2) the other case in which the two players share the decision-making process equally. In this paper, we examine which of the cases is better for the companies and where comes the value of the better case. To answer the research questions, we set up an optimal control theory model and derive an analytical solution. The analysis outcome indicates that the shared decision-making in general produces better results for both companies in the supply chain, and the value of the shared decision-making comes from more effective resource utilization than the dominated case.

• The KSFM Journal of Fluid Machinery
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• v.19 no.4
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• pp.54-62
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• 2016

This study presents an approach of tidal farming optimization using a numerical modelling method to simulate tidal energy extraction for 1MW scale tidal stream devices around Jangjuk-sudo, South Korea. The utility of the approach in this research is demonstrated by optimizing the tidal farm in an idealized scenario and a more realistic case with three scenarios of 28-turbine centered tidal array (named A, B and C layouts) inside the Jangjuk-sudo. In addition, the numerical method also provides a pre-processing calculation helps the researchers to quickly determine where the best resource site is located when considering the position of the tidal stream turbine farm. From the simulation results, it is clearly seen that the net energy (or wake energy yield which includes the impacts of wake effects on power generation) extracted from the layout A is virtually equal to the estimates of speed-up energy yield (or the gross energy which is the sum of energy yield of each turbine without wake effects), up to 30.3 GWh/year.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.8 no.2
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• pp.55-60
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• 2012

In many cases, geothemal wells will not be opened up a geothermal reservoir under such conditions that an extraction of geothermal energy is economically viable without any further measures. Geothermal wells often have to be stimulated, in order to increase productivity. For the non-volcanic area, such as Korea, the hydraulic stimulation is necessary to complete geothermal power plant. The analysis of induced seismic event showed that the thermal resource might have a much wider extent and a much higher generation potential than previously assumed. In order to record compressional and shear waves emitted during fracture stimulation, three-component geophones are placed in a seismometer. The recorded data from one seismometer is the convolution of the source magnitude, the transmission media, and the sensitivity of the instrument.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.3-32
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• 2008

The potential deep geothermal resources span a wide range of heat sources from the earth, including not only the more easily developed, currently economic hydrothermal resources; but also the earth's deeper, stored thermal energy, which is present anywhere. At shallow depths of 3,000~10,000m, the coincidence of substantial amounts heat in hot rock, fluids that heat up while flowing through the rock and permeability of connected fractures can result in natural hot water reservoirs. Although conventional hydrothermal resources which contain sufficient fluids at high temperatures and geo-pressures are used effectively for both electric and nonelectric applications in the world, they are somewhat limited in their location and ultimate potential for supplying electricity. A large portion of the world's geothermal resource base consists of hot dry rock(HDR) with limited permeability and porosity, an inadquate recharge of fluids and/or insufficient water for heat transport. An alternative known as engineered or enhanced geothermal systems(EGS), to dependence on naturally occurring hydrothermal reservoirs involves human intervention to engineer hydrothermal reservoirs in hot rocks for commercial use. Therefore EGS resources are with enormous potential for primary energy recovery using an engineered heat mining technology, which is designed to extract and utilize the earth's stored inexthermal energy. Because EGS resources have a large potential for the long term, United States focused his effort to provide 100GW of 24-hour-a-day base load electric-generating capacity by 2050.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.5
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• pp.39-45
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• 2013

Wind power is one of the fastest growing renewable energy sources. In these days, wind turbine shifts from onshore to offshore because the offshore wind farm has a abundant wind resource. However, offshore wind turbine is not easy to access, it has a long downtime when the failures of the wind turbine component occur. Therefore, the appropriate wind turbine maintenance plan is required to meet the economic and reliability of the components. This paper proposes the maintenance planning method based on the RCM(Reliability Centered Maintenance) to determine an economical maintenance cycle to satisfy the appropriate reliability of the wind turbine components. In order to compare the proposed method with the conventional RCM method, critical components are selected in the case study because they have a long downtime and a large amount of total cost.

• ETRI Journal
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• v.30 no.4
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• pp.576-586
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• 2008

In most parallel loops of embedded applications, every iteration executes the exact same sequence of instructions while manipulating different data. This fact motivates a new compiler-hardware orchestrated execution framework in which all parallel threads share one fetch unit and one decode unit but have their own execution, memory, and write-back units. This resource sharing enables parallel threads to execute in lockstep with minimal hardware extension and compiler support. Our proposed architecture, called multithreaded lockstep execution processor (MLEP), is a compromise between the single-instruction multiple-data (SIMD) and symmetric multithreading/chip multiprocessor (SMT/CMP) solutions. The proposed approach is more favorable than a typical SIMD execution in terms of degree of parallelism, range of applicability, and code generation, and can save more power and chip area than the SMT/CMP approach without significant performance degradation. For the architecture verification, we extend a commercial 32-bit embedded core AE32000C and synthesize it on Xilinx FPGA. Compared to the original architecture, our approach is 13.5% faster with a 2-way MLEP and 33.7% faster with a 4-way MLEP in EEMBC benchmarks which are automatically parallelized by the Intel compiler.

• The Journal of Fisheries Business Administration
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• v.39 no.3
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• pp.111-137
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• 2008

Fisheries resources living in inland have continuously reduced due to over-fishing and development thoughtless for the environment. Inland fisheries that target the fisheries resources have been also confronted by several problems such as insufficiency of inland fisheries management systems, inconsistent fisheries management system, inferior infrastructure of inland fisheries, and decreasing fishermen's real income. These problems have demotivated fishermen who want to focus on fishing and farming activation. Therefore, this paper provides alternatives of reorganization for turning to sound and healthy inland fisheries industries by reviewing Korean inland fisheries management systems. The reorganization should be preferentially granted resource management by water system considering geographical conditions, seed release, and establishment of fisheries order for maintenance of sound and healthy inland fisheries. Also, the reorganization should be moved toward the competitive strengthening of "company unit" for inland fisheries, the nourishment of fisher-oriented fisheries management system, strong relationship among inland fishermen, the systematic management of inland fisheries, the strengthening of guidance service for inland fisheries, the extension of infrastructure related to fisheries production, the development of inland fisheries policy including public people, and the improvement of inland fisheries system and law reflecting various users of inland fisheries.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.821-832
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• 2015

The aims of this study are to estimate the optimal vessel reduction scales and these direct economic effects of coastal and offshore fisheries in the Republic of Korea. To estimate respectively optimal fishing efforts of individual fishery by species in coastal and offshore fisheries, we adopted appropriate fishing power of each species published by National Fisheries Research and Development Institute and also considered biological and socio-economic factors such as the bycatch rate, the profit rate, the efficiency of resource use, the average age of fishing vessel, the intention of vessel reduction, and the annual changes in vessels by other factors. The direct economic effects of the optimal vessel reduction in coastal and offshore fisheries based on maximum sustainable yield and 2/3 maximum sustainable yield was calculated by a cost-benefit analysis. This study showed that optimal reduction numbers of vessels engaged in coastal and offshore fisheries were 4,431 and 374 vessels and the direct economic effects in coastal and offshore fisheries were about 371.7 and 569.4 billion won and these NPV and BCR were 111.7 billion won and 1.65 and 342.6 billion won and 4.97 respectively.