• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.7-11
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• 2008

The fluorescent lamp is one of a discharge lane that is used by electric discharge to transfer from electrical energy to light The fluorescent lamp needs a ballast stabilizer when turn it on because it has negative resistance. Characters of electric discharge and transformed characters of ballast stabilizer are connected closely. Therefore, bring out best design directive that consider economical efficiency and term of a application is very important for both characters matching. In this case, we will team to develop tester and functions for expression for recognizing the end of fluorescent lamp life to solve fire problem and losing efficiency of light when a fluorescent lamp goes the end of the expected its life span.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.103-106
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• 2006

This study investigates spalling properties of 60MPa class, high performance concrete, made with the various influential parameters, such as, blaine of cement, mineral admixture and polypropylene(PP) fiber contents. Totally 21 parameters of ${\phi}100{\times}200mm$ in size was fabricated; three specimens for variance in blaine of cement, 4 specimens for combination of mineral admixture type, along with 0.05, 0.1, 0.15% of fiber adding ratio. After that, one hour unloading fire test was conducted, and then spalling appearance and spalling degree of specimens was examined. Test showed that a specimen made with high blaine of cement(H) improved early strength but exhibited similar value to a specimen made with low blaine(L) at the age of 28 days, thus indicating comparable spalling appearance. In conclusion, spalling easily occur in higher strength and smaller particle shape of cement and mineral admixture.

• Journal of the Korea Safety Management & Science
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• v.9 no.4
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• pp.83-90
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• 2007

This study is to find out if it can be recycled for making better concrete. Therefore, waste paper as of newspaper and newspaper are added into concrete to see if waste paper-mixing concrete can have any particular characteristic. The test result of paper concrete was compared and analyzed through four kinds of tests such as compressive strength as of a fundamental one of concrete resistant capacity against heat. $200^{\circ}C,\;400^{\circ}C\;and\;600^{\circ}C$ heated concrete were compressively tested in order to find out concrete strength resistant to high temperature. heat capacity was also tested, based on the expectancy of its low conductivity. finally flexural strength test using four reinforced concrete beams with size of $20cm{\times}30cm{\times}160cm$ was made. And concrete property exposed to the temperature showed that there are almost not effect for the strength up to $400^{\circ}C$, but it was decreased down to 50% of the original condition. volume of paper mixed with concrete without relation to paper kinds of new and waste one.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.68-71
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• 2013

Reactive Powder Concrete (RPC) is an ultra high strength and high ductility cement-based composite material and has shown some promise as a new generation concrete in construction field. It is characterized by a silica fume-cement mixture with very low water-binder (w/b) ratio and very dense microstructure, which is formed using various powders such as cement, silica fume and very fine quartz sand (0.15~0.4mm) instead of ordinary coarse aggregate. However, the unit weight of cement in RPC is as high as 900~1,000 kg/㎥ due to the use of very fine sand instead of coarse aggregate, and a large volume of relatively expensive silica fume as a high reactivity pozzolan is also used, which is not produced in Korea and thus must be imported. Since the density of RPC has a heavy weight at 2.5~3.0 g/㎤. In this study, the modified RPC was made by the combination of ternary pozzolanic materials such as blast furnace slag and fly ash, silica fume in order to economically and practically feasible for Korea's situation. The fire resistance and structural behavior of the modified RPC exposed to high temperature were investigated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.160-161
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• 2013

Recently, the enviroment problem is serious due to the global warming phenomenon because of the greenhouse gas exhaustion. In addition, the effort to reduce the problem in the situation where the severity of the destruction of environment because of the indiscriminate picking of the that is the raw material of the cement, Accordingly, in the interior of a country, the industrial site using the artificial stone instead of the natural stone is increased. Thus the cement reduction amount of use and substitute material research is the urgent actual condition with the gas emission, which here it is generated in conducting compression molding in the building stone manufacturing process performance degradation phenomenon and fire resistance, and problem of the durability. limestone and aggregate and exhaustion of resource are emphasized is continued. In this research, the fly ash and waste porcelain is applied to the magnesia phosphate composite (MPC) and the characteristic of the artificial stone according to it tries to be looked into.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.251-254
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• 2001

In this paper, we analysed the properties change of electric wire when the thermal stress was applied to NFR-8 and FR-PVC [600] wire. Measurement is made of the attenuation of a light beam by smoke accumulating with in a closed chamber due to nonflamining pyrolytic decomposition and flaming combustion. Results are expressed in terms of specific optical density which is derived from a geometrical factor and the measured optical density a measurement characteristic of the concentration of smoke. Referenced documents were ASTM E662 standard test method for specific Ds generated by solid materials. The furnace control system shall maintain the required irradiance level under steady-state condition with the chamber door closed of 2.5${\pm}$0.04[w/$\textrm{cm}^2$] for 20 min. According to the results of the smoke density analysis of NFR-8 and FR-PVC the highest decomposition flaming smoke density range of NFR-8 and FR-PVC were 7.2 to 77.5 and 51.1 respectively. Nonflaming smoke density range of NFR-8 and FR-PVC were 100.4 to 112.2 and 126.5 to 398.8. The amount of carbon monoxide generated was found to be much higher in FR-PVC decomposition than in NFR-8 due to incomp1ete combustion of FR-PVC which has high content of carbon in compound.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.1
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• pp.85-92
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• 2000

Recently. there has been steadily applied in high-performance concrete using powder type admixture in construction field. It has been reported that high-performance concrete is likely to cause the spalling by fire more seriously due to the dense microstructure. In this paper, spalling properties of high-performance concrete with the kinds of admixture and polypropylene(PP) fiber contents are presented. According to the experimental results concrete contained no PP fiber take place in the form of the surface spalling, regardless of admixture. Concrete contained more than 0.05% of PP fiber and admixture do not take place the spalling, however the concrete using silica fume do spalling. Concrete using blast furnace slag have good performance in spalling resistance. It is found that residual compressive strength has 60~70% of its original strength when spalling do not occur. Although specimens after exposed at high temperature are cured at water for 28days, they do not recover their original strength.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.165-173
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• 2008

In order to promote the practicality of high-rise steel buildings, the development of structural system which have the better fire resistance, the changeable plan, and the quality control of construction with general composite beams is needed. In this research, new semi-slim floor which the defect of general slim floor was complemented was evaluated to investigate the concrete integration with slim-flor beam and the flexural performance. 5 simply supported semi-slim floor beam tests were performed with parameters; structural form of slab support beam, slab thickness, with or without web opening, and shear connection. Experimental results showed that all specimen s had good ductile behavior.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.928-934
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• 2008

Resently, Fiber Reinforced Concrete is used for not only preventing crack of concrete but also reinforcing general methods. Steel Fiber and PP(poly-propylene) Fiber are usually used as fiber reinforced materials. However, using these materials for shotcrete on Railway tunnel can cause some problems such as damage of pressure hose and shotcrete rebound. In addition, Steel fiber is an expensive material and it can cause safety problems during applying to shotcrete. PP Fiber can cause a problem in fiber balling during applying to shotcrete railway tunnel construction. A purpose of the research is applying a development of PET(Poly Etylene Terephtalate) fiber by recycling pet bottles to the shotcrete tunnel exposed to explosion spalling. To investigate the reinforcement effect of the PET fiber, some basic tests are accomplished to physical properties and explosion spalling by fire. As a result of the tests, a concrete mixing the PET fiber has stronger resistance effect in the explosion spalling by high temperature than another strong fiber concrete does, and that the former concrete is also equal or more effective on the result of the above tests to physical properties like compression and strain than the latter one is demonstrated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1619-1625
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• 2018

Portable electronic devices secondary batteries can cause fire and explosion due to micro-current change in addition to the situation of short-circuit inrush current, safety can not be secured with a general operation limited current fuse. Therefore, in secondary battery, it is necessary for the protector to satisfy both the limit current type operation in the open-short-circuit inrush current and the current detection operation characteristic in the micro current change situation and for this operation, a fuse for the current detection type secondary battery protection circuit can be applied. The purpose of this study is to design a protection device that operates stably in the hazardous situation of small capacity secondary battery for portable electronic devices through the design of low melting fuse elements alloy of sensing type fuse and secures stability in abnormal current state. As a result of the experiment, I-T and V-T operation characteristics are satisfied in a the design of the alloy of the current sensing type self-contained low melting point fuse and the resistance of the heating resistor. It is confirmed that it can prevent accidents of short circuit over-current and micro current change of secondary battery.