• Economic and Environmental Geology
• /
• v.51 no.2
• /
• pp.185-201
• /
• 2018

Nuclear power plants(NPP) are constructed and operated to ensure safety against natural disasters and man-made disasters in all processes including site selection, site survey, design, construction, and operation. This paper will introduce a series of efforts conducted in Korea Hydro and Nuclear Power Co. Ltd., to assure the safety of nuclear power plant against earthquakes and other natural hazards. In particular, the present status of the earthquake, fault, and slope safety monitoring system for nuclear power plants is introduced. A earthquake observatory network for the NPP sites has been built up for nuclear safety and providing adequate seismic design standards for NPP sites by monitoring seismicity in and around NPPs since 1999. The Eupcheon Fault Monitoring System, composed of a strainmeter, seismometer, creepmeter, Global Positioning System, and groundwater meter, was installed to assess the safety of the Wolsung Nuclear Power Plant against earthquakes by monitoring the short- and long-term behavioral characteristics of the Eupcheon fault. Through the analysis of measured data, it was verified that the Eupcheon fault is a relatively stable fault that is not affected by earthquakes occurring around the southeastern part of the Korean peninsula. In addition, it was confirmed that the fault monitoring system could be very useful for seismic safety analysis and earthquake prediction study on the fault. K-SLOPE System for systematic slope monitoring was successfully developed for monitoring of the slope at nuclear power plants. Several kinds of monitoring devices including an inclinometer, tiltmeter, tension-wire, and precipitation gauge were installed on the NPP slope. A macro deformation analysis using terrestrial LiDAR (Light Detection And Ranging) was performed for overall slope deformation evaluation.

• Korean Chemical Engineering Research
• /
• v.57 no.6
• /
• pp.781-789
• /
• 2019

There are frequent accidents by chemicals during laboratory experiments and pilot plant and reactor operations. It is necessary to find and comprehend relevant information to prevent accidents before starting synthesis experiments. In the process design stage, reaction information is also necessary to prevent runaway reactions. Although there are various sources available for synthesis information, including the Internet, it takes long time to search and is difficult to choose the right path because the substances used in each synthesis method are different. In order to solve these problems, we propose an intelligent synthetic path search system to help researchers shorten the search time for synthetic paths and identify hazardous intermediates that may exist on paths. The system proposed in this study automatically updates the database by collecting information existing on the Internet through Web scraping and crawling using Selenium, a Python package. Based on the depth-first search, the path search performs searches based on the target substance, distinguishes hazardous chemical grades and yields, etc., and suggests all synthetic paths within a defined limit of path steps. For the benefit of each research institution, researchers can register their private data and expand the database according to the format type. The system is being released as open source for free use. The system is expected to find a safer way and help prevent accidents by supporting researchers referring to the suggested paths.

• Korean Chemical Engineering Research
• /
• v.51 no.2
• /
• pp.240-244
• /
• 2013

Although forward osmosis desalination technology has drawn substantial attention as a next-generation desalination method, the energy efficiency of its draw solution treatment process should be improved for its commercialization. When ammonium bicarbonate is used as the draw solute, the system consists of forward-osmosis membrane modules, draw solution separation and recovery processes. Mixed gases of ammonia and carbon dioxide generated during the draws solution separation, need to be recovered to re-concentrate ammonium bicarbonate solution, for continuous operation as well as for the economic feasibility. The diluted ammonium bicarbonate solution has been proposed as the absorbent for the draw solution regeneration. In this study, experiments are conducted to investigate performance and features of the absorption corresponding to absorbent concentration. It is concluded that ammonium bicarbonate solution can be used to recover the generated ammonia and carbon dioxide. The results will be applied to design and operation of pilot-scale forward-osmosis desalination system.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.26 no.2
• /
• pp.95-103
• /
• 2018

As a guideline for desulfurization and dehumidification pretreatment facility for optimizing utilization of biogas, the $H_2S$ concentration is set at 150 % which can be treated with iron salts, dehumidification is the optimum value for generator operation, and the relative humidity applied at the utilization of biogas in EU is set at 60 %. We have set up the generator facility guidelines to optimize utilization of biogas. The appropriate amount of biogas should be at least 90 % of the total gas generation, and the capacity of generator facility should be set at 20~30 %. In order to equalize the pressure of the incoming gas the generator, a gas equalization tank should be installed and the generator room average temperature should be kept at $45^{\circ}C$ or less. Since the gas is not produced at a certain methane concentration in the digester, the efficiency is lowered. Therefore, it is required to install an air fuel ratio control system according to the change in methane concentration. Therefore, it is necessary to compensate for the disadvantages of biogasification facilities of organic waste resources and optimize utilization of biogas and improve operation of facilities. This study was conducted to optimize biogas utilization of type of organic waste(containing sewage sludge and food waste, animal manure), investigate the facilities problem and propose design, operation guidelines such as pre-treatment facilities and generators.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.9 no.5
• /
• pp.49-58
• /
• 2010

The traffic signal controllers being used in the domestic currently are being manufactured based on the korean national police standard which was developed for controlling the quad-light traffic signal having the red, yellow, left-turn arrow, and green lights. But according to the national policy for the traffic operation, they have to be changed to be able to switch the tri-light signal having red, yellow and green lights. In this study, a new tri-light traffic signal controller was designed and developed by the way improving the Signal Control Unit of the existing quad-light standard traffic controller. The Load Signal Unit(LSU) was improved to output 6 signals which are the two assemblies of three signal indications having the red, yellow, and green lights. To enough traffic signals output to control each directional movements and the various transport modes which are car, bus, bike, and pedestrian etc., the connector bus system was designed to be able to accommodate maximum 96 signals outputs being constructed by 16 LSUs. Flasher device was developed to be able to support maximum 32 red signals. In the software, the communication protocol between traffic control center and the traffic signal controller was improved and new signal map code values were defined for the developed LSU controlling the quad-light traffic signal. A model of the quad-light traffic signal controller developed and was tested three operations, protocol-operation, remote-command and control-mode. The test result operated all of them successfully.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.8 no.4
• /
• pp.129-137
• /
• 2000

In this study, biological treatment process of MWWT(Municipal wet-waste Treatment) has been developed through a moduling of the containerized closed ATAD(Auto thermal aerobic digestion) system & closed vertical dynamic acerator, which were used for food waste and cattle manure, respectively. Though biological process has several advantages such as low concentrations of heavy metals and salts, proper and stable C/N ratio and constant reaction rate against the process treating two wastes separately, it has a obstacles of salt concentration and much usage of bulking agent such as wood chip. After rapid oxidation in the boxed tower reactor for 5 days, the content of sewage sludge would be reduced 65% on around, might be mixed with the food waste that had been treated in the static closed reactor during 6 days and put in the secondary static reactor for curing. During composting process, the odor contained in the gas generated from the reactor was removed by passing it through a biofilter as well as the leachate was treated in the wastewater treatment facility. Consequently, it seemed to be possible to compost sewage sludge at mild and stable operating condition and at low cost through the biological ATAD process resulting in the production of organic compost satisfying the specifications regulated by itself.

• Journal of the Institute of Convergence Signal Processing
• /
• v.16 no.2
• /
• pp.74-82
• /
• 2015

In this study, a BMW plant process control system model which produces BMW is suggested and the BMW plant process controller with the following functions is developed. The first function is to operate the electronic overload relays to stop the blower for a certain period of time and to re-operate it again when the blower is overloaded. The second function is to close the motor operated valve automatically in case of power failure to prevent the circulation from the guided tank to the compost throwing tank and to block leak from the compost throwing tank due to the failure of ball valve. The third function is to transfer produced BMW from the concentration tank to 4 storage tanks for automatic managing of the BMW output. A device to measure the signal of the BMW plant process controller and a test equipment are developed. The designed BMW plant process controller is checked to see if it operates correctly according to the design specifications. The sequence control method based on BMW plant process controller is developed at a low cost in this study, so it is expected to bring improvements in the stability and the efficiency of system and to cause reductions in the operation and the management costs in the future.

• Tunnel and Underground Space
• /
• v.27 no.1
• /
• pp.12-25
• /
• 2017

In local underground mines heavily depending on the natural ventilation, ducted fan auxiliary ventilation system is strongly recommended instead of the total mine ventilation system requiring large capital and operating costs. Optimizing the installation of ducted fans in series in long large-opening mines is required to assure the economy and efficiency of the ventilation system. The two most critical design parameters for optimization are the wall separation distance and gap length between adjoining ducts. This study aims at deriving the optimal values for those two parameters concerning the economic and environmental aspects through the extensive CFD analysis, which minimizes pressure loss, leakage and entrainment of the contaminated air in the gap space. The ranges of the wall separation distance and gap length for study are selected by taking into consideration the existing recommendations and guidelines. The ultimate goal is to optimize the auxiliary ventilation system using ducted fans in series to provide a reliable and efficient solution to maintain clean and safe workplace environment in local long underground mines.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.2
• /
• pp.821-828
• /
• 2011

This paper developed the algorithm for improving the performance the auto pilot in the autonomous vehicle system consisting of the Track keeping control, the Automatic steering, and the Automatic mooring control. The automatic steering is the control device that could save the voyage distance and cost of fuel by reducing the unnecessary burden of driving due to the continuous artificial navigation, and avoiding the route deviation. During the step of the ship autonomic navigation control, since the wind power or the tidal force could make the ship deviate from the fixed course, the automatic steering calculates the difference between actual sailing line and the set course to keep the ship sailing in the vicinity of intended course. first, we could get the transfer function for the modeling of ship according to the Nomoto model. Considering the maneuverability, we propose it as linear model with only 4 degree of freedoms to present the heading angle response to the input of rudder angle. In this paper, the model of ship is derived from the simplified Nomoto model. Since the proposed model considers the maximum angle and rudder rate of the ship auto pilot and also designs the Fuzzy controller based on existing PID controller, the performance of the steering machine is well improved.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.21 no.6
• /
• pp.129-134
• /
• 2021

Recently, the demand for electricity is gradually increasing due to the rapid industrial development and the improvement of living standards. In the case of Korea, which is highly dependent on fossil fuels due to such a surge in electricity demand, reduction and freezing of greenhouse gas emissions due to international environmental regulations will immediately lead to a contraction in industrial activities. Accordingly, there are many difficulties in competition with advanced countries that want to link the environment with the country's industrial production activities, and the development of alternative energy as a countermeasure is of great interest around the world. Among these new power generation methods, small-scale power generation facilities with relatively small capacity include photovoltaic generation, wind power generation, and fuel cell generation. Among them, the fuel cell attracts the most attention in consideration of continuous operation, high power generation efficiency, and long-term durability, which are important factors for practical use. Therefore, in this paper, the fuel cell power generation system was researched and constructed by designing the power conversion circuit necessary to finally obtain the AC power used in our daily life by using the DC power generated from the fuel cell as an input.