• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1195-1200
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• 2020

The DOM (: Digital Optical Method), which measures the turbidity of chimney smoke, is a method of calculating the turbidity by setting the area to be measured and the contrast area using a low-cost digital camera that can be easily obtained. However, it is difficult to measure clouds and white smoke in a cloudy sky. In this paper, we develop a background sky type model that can represent the background sky and classify the type by periodically photographing it with a digital camera to solve this problem. In addition, based on the model, we develop a filter to optimize white smoke image and prove its excellence through experiments.

• Journal of the Korean Society of Safety
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• v.37 no.2
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• pp.69-75
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• 2022

Fire-alarm systems are safety equipment that facilitate rapid evacuation and early suppression in case of fire. It is highly desirable that fire-alarm systems have low false-alarm rates and are thus reliable. Until now, researchers have attempted to improve detector performance by applying new technologies such as IoT. To this end, IoT-based fire-detection systems have been developed. However, due to scarcity of large-scale operational data, researchers have barely studied malfunctioning in fire-alarm systems or attempted to reduce false-alarm rates in these systems. In this study, we analyzed false-alarm rates of smoke/temperature detectors and unwanted fire-alarm signal patterns at K institution, where Korea's largest IoT-based fire-detection system operates. After analyzing the fire alarm occurrences at the institution for five years, we inferred that the IoT-based fire-detection system showed lower false-alarm rates compared to the automatic fire-detection equipment. We analyzed the detection pattern by dividing it into two parts: normal operation and unwanted fire alarms. When a specific signal pattern was filtered out, the false-alarm rate was reduced to 66.9% in the smoke detector and to 46.9% in the temperature detector.

• Fire Science and Engineering
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• v.22 no.3
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• pp.194-200
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• 2008

In order to design and operate successfully the pressure differential system for smoke control which uses difference of pressure between compartments of building, architectural factors affecting the pressure field of building should be examined and the stack effect is one of the important factors. The field experiments on pressure field in two buildings of 21 stories and 31 stories in summer and winter season with regard to on/off condition of the pressure differential system are carried out to evaluate the influence of stack effect to evacuation and smoke management of high-rise building. In winter season when the stack effect increases, as the pressure differential system starts to operate, the pressure in upper stair rises largely due to the combination effect of the air infiltration from lobby to stair and the stack effect.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.180-184
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• 2016

Legislative and regulatory actions regarding the exhaust gas from ships are being strengthened by both international organizations and national governments, to protect human health and the environment. Exhaust gas traps are excluded from exhaust gas regulation applications, but, recently, the United States, Britain, and other developed countries have examined a variety of ways to improve the system, including the introduction of electric propulsion systems to prevent air pollution generated by naval ships. This study investigates a large number of smoke problems of naval diesel engines to verify the effect of improving the nozzle characteristics. An exhaust gas emission measurement method to determine the quality of pollutant exhaust gas generated during low-load operation is proposed through the research methodology of the smoke problem. It was confirmed that the emissions value is improved by decreasing the nozzle hole diameter and increasing the injection pressure. At the same time, the flow rate decrease equation and setting up a test memo based on the nozzle diameter confirmed that the fuel consumption, to which the nozzle diameter in the flow path is related, is reduced.

• Fire Science and Engineering
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• v.33 no.3
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• pp.74-83
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• 2019

In the U.S., the pressurization of elevator shaft was developed in 1972 to allow vulnerable people, such as the elderly and weak who could not use escape stairs in case of fire, to evacuate. It is an advantage in terms of space saving by not using vertical ducts. This study drew the problem of the pressurization of elevator shaft based on the existing domestic patents and proposed improvements. The smoke control volume calculation method is proposed by using vertical modeling. Leakage gaps in elevator doors need to be reviewed through experimental data or actual data. The evacuation floor was divided, the openings in the elevator machine room were automatically closed to the fire signal and the relief damper was installed to improve the performance. The improved method functions as the smoke control damper supplying the air flow rather than maintaining the differential pressure. To increase reliability of the research results, the procedure was performed to verify by using Contam.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.20-24
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• 2017

In this study, we have performed the Cone Calorimeter test in accordance with ISO 5660-1 to check the combustion characteristics of building flooring materials. The fire risk of these materials were evaluated by construction code, KFI criteria and standards of flame retardant performance. When samples exposed to external heat flux, all samples consumed a lot of Oxygen for a long time. So heat release from sample burning continued so long. And also all samples produced so much smoke. Even though a few samples were satisfied with only peak heat release rate criteria, all 8 samples were not satisfied with criteria of peak heat release rate and total heat released together. The results of 5 min total heat released were $15.9MJ/m^2{\sim}5.9MJ/m^2$. It menas the results are more than 2~6 times higher than the criteria. The results of 10 min total heat released were $30.1MJ/m^2{\sim}100.8MJ/m^2$. It means the results are more than 3~12 times higher than the criteria. 6 of 8 samples were not satisfied with Dm.corr.(corrected maximum smoke density) criteria. The building flooring materials which we used for this test ignited very fast and the burning continued so long. It means these samples are susceptible to fire.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.12 no.2
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• pp.1-41
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• 2001

The effect of smoking on the quality sausage Sausages were prepared from beef, port, chickens, games, fish and shellfish with polyphosphate salt and spices. Sausage history goes back to 3,000 years of age. The procedure of sausage 1) Meat Curing 2) Meat Control 3) Add Spices 4) Permissible Ingredients 5) Grinding 6) Mixing Emulsion 7) Stuffing 8) Showing 9) Smoking 10) Cooking 11) Drying 12) Packaging Sausage Product to get information on the effect of smoking onto the quality of meat produces. Sausage was smoked under a given conditions. Smoking was conducted as 35f$^{\circ}C$to 6$0^{\circ}C$ the related humidity of smokehouse was still at 60 to 70 percent. Results are as follows: 1. The Penetrated smoke in sausage was prolonged < p.<0.02 when sausage was smoked 2hours at 60~$65^{\circ}C$ the penetrated amount of free acetone in sausage was 0.5mg%. 2. Peroxide value of sausage as heating treatment both at 3$0^{\circ}C$ and at 5$0^{\circ}C$ was prolonged. 3. When sausage was heated at 3$0^{\circ}C$, bacteria of sausage increased In number while at 60~$65^{\circ}C$ bacteria of sausage increased In number fourteen hours. 4. When sausage was treated with smoking the distribution of free amino acids in sausage was changed markedly. 5. The longer smoking time of the products was the higher the content. 6. In case of oak wood smoke flavoring all of test samples. 7. Rapid decrease of does-response mutagenic curve of the smoke flavoring of oak wood and apple wood by in the peak of curve and phenol in the smoke flavoring. Continuous efforts are required to make sausages easily in the butcher shops and in the restaurants. 8. Sausage texture evaluation has 13 rules. It is Elasticity, Surface Moisture, Surface Smoothness, Center Hardness, Skin Toughness, Cohesiveness, Denseness, Moisture Release, Cohesiveness of Mass, Lumpiness, Graininess (of Contents), Skin separation, Oiliness and sensory 11 rules evaluation is color, texture, mold, flavor, sweet test, salty, sourness, bitter, and savory taste. 9. Smoked, component, peroxide value, bacteria, color, free amino acid, tenderness, flavor, shrinkage are important values.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.9
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• pp.870-875
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• 2015

Diesel engines are widely used due to superior power and fuel consumption, however there are many challenges in exhaust gas management. Exhaust gas recirculation (EGR) is the most effective technique for reducing mono-nitrogen oxide (NOx) emissions in a diesel engine, in comparison with other catalytic technologies. In addition, the technology has a number of advantages in terms of economic efficiency and implementation. In this study, the effects on the power and exhaust characteristics of diesel engines equipped with EGR systems were investigated. It was found that as the EGR rate increased, horsepower expressed as IHP and BHP decreased. The net effect of the application of EGR was measured at various engine speeds. EGR technology caused decreases in BHP of around 9% during low engine speed and 3.5% during high engine speed. Additionally, NOx emissions reduced as the EGR rate increased, and increased as engine speed increased. However, smoke emissions increased as the EGR rate increased, and decreased as engine speed increased. The optimum operating conditions and ERG rate to simultaneously achieve minimum NOx and smoke emissions were investigate. It was found that as the EGR rate increased, optimal operating speed for minimal NOx and smoke also increased. Keywords: Diesel engine, Exhaust gas recirculation, Power perfomance, Emission characteristics, NOx, Smoke

• Proceedings of the Safety Management and Science Conference
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• 2006.11a
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• pp.325-336
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• 2006

This research analyzes clean room major fire prevention standard of clean Room (FM, IRI, and NFPA Code), the structure of Performance-Based Fire Safety Design (PBD) applied the korean fire industry situation. Performance-Based Fire Safety can operate effectively the performance of fire protection equipment & building design, so the fitness of fire safety system can be embodied by operating this. moreover, cost to be consume fire safety of real building can reduce and Performance-Based Fire Safety is considered to important technique in fire protection field. A fire in a clean room may cause a serious loss by spreading smoke particles. We will be investigated by using a computational fluid dynamics, for loss prevention by smoke spreading from one fire area to another for clean room and compared the Performance-Based Fire Safety Design with the prescriptive code design. The methodology of fire safety performance-based fire safety design and guarantee of many kinds design skill of fire system and developing design procedure will be very serious one in order to improve efficiency of domestic system. Therefore, This research will be contributing to secure safety of clean room and to set up the performance-based fire safety design in Korea by regulation for the performance-based fire safety design effectively.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.135-143
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• 2008

Recently as the testing of fire detector used the testing device for fire detector, there are something the matter in the perception function loss of fire detector, structure and form of the testing device for fire detector. The problem at oxidation of emitting smoke ashes hazardous article part and so on that checking person absorbs be. In this paper the problem or the conventional the examination equipment of fire detectors is analysed and researched. To solve these problems after the theoretical study and design and paint drawing of equipment the prototype of composite examination equipment of fire detectors was made. After compared with the conventional, part that improve of composite examination equipment of fire detectors are verified through the examination. In the future it will be useful the operation state and correct operation time of the fire detectors are measured after the research about the quality of the material and transparency of bellows cover is done.