• Journal of Korean Society of Environmental Engineers
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• v.35 no.2
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• pp.115-123
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• 2013

Stoker type incinerator is one of the most popular one used as municipal solid waste (MSW) incineration because, in general, it is quite suitable for large capacity and need no preprocessing facility. Nowadays, however, since the combustible portion of incoming MSW increases together with the decrease of the moisture content due to prohibition of directly burying food waste in landfill, the heating value of waste is remarkably increasing in comparison with the early stage of incinerator installation. Consequently, the increased heating value in incinerator operation causes a number of serious problems such as reduction of waste amount to be burned due to the boiler heat capacity together with the significant NO generation in high temperature environment. Therefore, in this study, a series of numerical simulation have been made as parameters of waste amount and the fraction of moisture in air stream in order to investigate optimal operating condition for the resolution of the problems associated with the high heating value of waste mentioned above. In specific, a detailed turbulent reaction flow field calculation with NO model was made for the full scale incinerator of D city. To this end, the injection method of moisturized air as oxidizer was intensively reviewed by the addition of moisture water amount from 10% and 20%. The calculation result, in general, showed that the reduction of maximum flame temperature appears consistently due to the combined effects of the increased specific heat of combustion air and vaporization heat by the addition of water moisture. As a consequence, the generation of NOx concentration was substantially reduced. Further, for the case of 20% moisture amount stream, the afterburner region is quite appropriate in temperature range for the operation of SNCR. This suggests the SNCR facility can be considered for reoperation. which is not in service at all due to the increased heating value of MSW.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.562-574
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• 2012

Simulation validation techniques which have been employed in most studies are statistical analysis, which validate a model with mean or variance of throughput and resource utilization as an evaluation object. However, these methods have not been able to ensure the reliability of individual elements of the model well. To overcome the problem, the weighted F-measure method was proposed, but this technique also had some limitations. First, it is difficult to apply the technique to complex system environment with numerous values of interarrival time because it assigns a class to an individual value of interarrival time. In addition, due to unbounded weights, the value of weighted F-measure has no lower bound, so it is difficult to determine its threshold. Therefore, this paper propose weighted F-measure technique with cluster analysis to solve these problems. The classes for the technique are defined by each cluster, which reduces considerable number of classes and enables to apply the technique to various systems. Moreover, we improved the validation technique in the way of assigning minimum bounded weights without any lack of objectivity.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.285-291
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• 2015

FTMS, TCS, ITS equipment such as high-pass highway are just a situation that does not lack traceability and passive surveillance is related to fault DB has so far consisted of an integrated operations management to maximize utilization of the facility. In addition, there is no replacement parts are replaced when a failure occurs, increasing the number of parts and repair time I have trouble growing, and becoming a service interruption whenever you replace each time. In this study, proactively manage the failure history of a highway facility ITS tries to preventive maintenance. Therefore, the error history is based on the reliability of the high-pass facilities theory to calculate the reliability of the system through a systematic statistical analysis Operational Availability. The fault number and the time the replacement period through the estimate decreases and can reduce the budget expenses by securing the spare parts quantity, establish a management plan in part by improving the quality of the system through constant preventive maintenance, quality of service at all times It may direct the non-stop operation state of the available state.

• Environmental and Resource Economics Review
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• v.17 no.2
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• pp.381-418
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• 2008

This study revisits the meaning of energy security by examining the oil market supply and demand conditions of petroleum products and refinery capacity of three Northeast Asian countries(Korea, China, Japan). In 2006, 10.6 million bid of excess demand occurred and is expected to be 15~22 million bid by the year 2030 in this regional oil market. Different oil demand is caused mainly by the different demands for various petroleum products based on each country's economic structures. If the demands are ranked according to their petroleum products, Chinese case shows gasoil > gasoline > fuel oil> LPG > naphtha > Kero/jet and Japanese case shows gasoil > gasoline> naphtha> Kero/jet > fuel oil > LPG, while Korean case shows naphtha> gas oil > fuel oil > LPG > Kero/jet > gasoline, respectively. Total CDU(Crude Distillation Unit) capacity of three northeast asian countries also have been examined in this respect. This study points out the importance of the information on oil demand and supply, on petroleum products and refinery capacities of the three Northeast Asian countries to enhance the security of the oil market in this region.

• Journal of the Korea Institute of Building Construction
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• v.11 no.6
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• pp.530-537
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• 2011

The purpose of this study is to examine material performance of fiber reinforced cement composite for mass production. It is necessary to manufacture SHCC(Strain Hardening Cement Composite) by batch plant for field application and mass production. For the study, a mock-up test of SHCC manufactured in the batch plant was conducted, and the performance was compared with SHCC manufactured in the laboratory. Assessment items were freshness and hardening properties. Specifically, direct tensile test machine was used for performance verification of SHCC. As a result, there was a tendency of less satisfactory fiber dispersion and performance of strain hardening compared with the performance of SHCC manufactured in the laboratory. To address this, dry mixing and mortar mixing time should be increased compared to laboratory mixing, and injection time of an agent such as a water reducing agent should be properly controlled according to mixing combination, or the capacity to secure dispersion and homogeneity of material.

• Nuclear Engineering and Technology
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• v.21 no.1
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• pp.18-31
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• 1989

To analyze the impact of air pollution control on electricity generation cost, a computer program was developed. POGEN calculates levelized discounted power generation cost including additional air pollution control cost for coal power plant. Pollution subprogram calculates total capital and variable costs using governing equations for flue gas control. The costs are used as additional input for levelized discounted power generation cost subprogram. Pollution output for Rue Gas Desulphurization direct cost was verified using published cost data of well experienced industrialized countries. The power generation costs for the year 2001 were estimated by POGEN for three different regulatory scenarios imposed on coal power plant, and by levelized discounted power generation cost subprogram for nuclear power. Because of uncertainty expected in input variables for future plants, sensitivity and uncertainty analysis were made to check the importance and uncertainty propagation of the input variables using Latin Hypercube Sampling and Multiple Least Square method. Most sensitive parameter for levelized discounted power generation cost is discount rate for both nuclear and coal. The control cost for flue gas alone reaches additional 9-11 mills/kWh with standard deviation less than 1.3 mills/kWh. This cost will be nearly 20% of power generation cost and 40% of one GW capacity coal power plant investment cost. With 90% confidence, the generation cost of nuclear power plant will be 32.6-51.9 mills/kWh, and for the coal power plant it will be 45.5-50.5 mills/kWh. Nuclear is favorable with 95% confidence under stringent future regulatory requirement in Korea.

• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.9-14
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• 2021

This paper discovers the energy loss factors through the insulation diagnosis of houses or buildings, and proposes directions for energy efficiency improvement. The energy efficiency factor of a building consists of insulation diagnosis, thermal bridge diagnosis, window diagnosis, airtight diagnosis, and equipment diagnosis. Among the residents and facilities in the energy welfare blind spot, an energy efficiency diagnosis was conducted for one senior citizen building located in Naju-si, Jeollanam-do, and energy efficiency diagnosis was conducted after insulation was installed. Energy measurement, diagnosis and analysis were performed using the IoT-based integrated wired/wireless energy diagnosis platform, Energy Finder. As a result of comparison, an overall energy saving rate of 16.38% was achieved. Annual heating energy consumption per unit area decreased from 333.51kWh before construction to 277.35kWh after construction, and annual cooling energy consumption per unit area decreased from 5.51kWh before construction to 5.22kWh after construction. The annual primary energy consumption per unit area decreased from 464.52kWh before construction to 403.69kWh after construction, and the annual energy cost was reduced from 3,063,307.14 won before construction to 2,641,072.49 won after construction. The additional improvement work is needed on the standards affecting energy efficiency other than insulation.

• Korean Security Journal
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• no.30
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• pp.33-60
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• 2012

False alarm of Electronic security causes various serious side effects such as decrease of electronic security guard's morale caused by unnecessary mobilization, increase of fatigue caused by workload increase, increase of electronic security company owner's management burden and decrease of electronic security service utilization rate caused by customer's distrust. Therefore, the study considered the Korean regulation related with false alarm of electronic security and proposed actual status of false alarm and measure for it. The study proposed systematic resolution assignments and political assignments in relation with the measure for false alarm. Systematic resolution assignments are as follows. First, electronic security company should construct electronic security system accurately from the initial step of security consulting and security planning related with target facility. Second, it is necessary to encourage installation and operation of video monitoring system. Third, sensor wiring should be separated. Fourth, the measures for false alarm depending on main system causes should be prepared. It is necessary to encourage the installation of 'arming disarming alarm sound' generator. In addition, the measures for false arm depending on the characteristics of sensor should be prepared and standardized. Fifth, system maintenance should be reinforced. Political assignments related with the measures for false alarm are as follows. First, it is necessary to reinforce education & training. Individual nurturing & education process should be run by electronic security company or the education focusing on the measure for false alarm should be performed in job training defined in "Security Industry Act". Second, it is necessary to establish and reinforce legal regulation and establish device. If police authority standardizes the documents related with false alarm, provides their forms and requires them for periodical reports or documents, it is expected that good measures for false alarm will be prepared on the basis of actual data in the future. Third, cooperation organization to discuss the measures for false alarm like 'Conference for False Alarm of Electronic Security' should be organized and operated. Fourth, interest and role of electronic security company and electronic security supervisor should be enlarged.