• Korean Journal of Heritage: History & Science
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• v.48 no.4
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• pp.62-73
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• 2015

The Tae-Jo Geonwolleung is the tomb of the first king Tae-Jo of the Joseon Dynasty in the complex of the Royal Tombs of the Joseon Dynasty which is listed in World Heritage, and it contains various types of stone properties. The material of the stone properties consist of a single type of medium-grained biotite granite, however, each properties have different intensity and types in deterioration phenomena according to their locations and purposes. The major deterioration types of the stones are analyzed as physical decomposition and biodeterioration. The exfoliation, breaking-out and granular decomposition are widespread types of the deterioration throughout the entire burial mound stone properties and surrounding stone properties. On the other hands, the colonization of mosses and plants, and contamination by foreign materials are found more frequent in the burial mound stone properties as these stones are in contact with the soil of the tomb mound and moisture in the soil helped biodeterioration. It is suggested that anti-biology treatment and physical reinforcement are applied to the deteriorated stones to prevent further damage on the stone components of the tomb.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.532-544
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• 2023

Purpose: To identify and evaluate the risk of chemical fire causative substances by using thermal analysis methods (DSC, TGA) for the hazards and physical property changes that occur when newly used biofuels are mixed with existing fuels It is to use it for identification and evaluation of the cause of fire by securing data related to the method and the hazards of the material according to it. Method: The research method used in this experiment is the differential scanning calorimeter (DSC: Difference in heat flux) through quantitative information on the caloric change from the location, shape, number, and area of peaks. flux) was measured, and the weight change caused by decomposition heat at a specific temperature was continuously measured by performing thermogravimetric analyzer (TGA: Thermo- gravimetric Analyzer). Result: First, in the heat flux graph, the boiling point of the material and the intrinsic characteristic value of the material or the energy required for decomposition can be checked. Second, as the content of biodiesel increased, many peaks were identified. Third, it was confirmed through analysis that substances with low expected boiling points were contained. Conclusion: It was shown that the physical risk of the material can be evaluated by using the risk of biodiesel, which is currently used as a new energy source, through various physical and chemical analysis techniques (DSC + TGA).In addition, it is expected that the comparison of differences between test methods and the accumulation and utilization of know-how on experiments in this study will be helpful in future studies on physical properties of hazardous materials and risk assessment of materials.

• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.2
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• pp.91-102
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• 1997

In order to evaluate the effects of aging on the ignition performance, pyrotechnic igniters were separated from twelve-year-old, fifteen-year-old, and sixteen-year-old live rocket motors. The characteristic values of the ignition material were measured, and the firing tests of the igniters were performed. The moisture content, the outer dimension, the crush strength, the thermal decomposition characteristics, and the heat of formation the B/$KNO_3$ ignition pellet were measured. The crush strength was increased and the heat of formation was reduced as aged, but no change was detected for other characteristic values. The burning test results of the igniter pellet in the closed bomb and the inert motor showed that the burning rate of the ignition pellet was increased by 10%, and the integration of pressure $P_t$ of the p-t curve was reduced by 15% for aged samples. It was inferred that the burning rate was increased as the crack was appeared in the pellet and $P_t$ could be proportionally decreased with the heat of explosion.

• Journal of Biosystems Engineering
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• v.30 no.4 s.111
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• pp.235-241
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• 2005

For better and large utilization of rice husk, the production and consumption status, differences in chemical composition and heating value due to region and variety, and thermogravimetric characteristic of rice husk were studied. In addition, the differences in chemical composition due to region and variety and the crystallization characteristic of rice husk ash were also studied. Approximately 800,000 M/T of rice husk was produced per year in Korea, which is about $18\%$ of the paddy production by weight. Noticeable varietal and regional difference pattern in chemical composition was not found among the domestic rice husk samples. Their average ash content and higher heating value were $16.4\%$ and 16,660 kJ/kg by dry basis, respectively. A relation seemed to exist between the carbon content and higher heating value. Noticeable difference pattern in chemical composition was not found among the domestic rice husk ash samples. The $SiO_2$ contents were a little low, the maximum being $92.9\%,$ and the contents of major components such as CaO, MgO, and $K_2O$ were also lower compared with foreign rice husk ash due to the deficiency of compost matters in domestic soils. Thermogravimetry study showed the thermal decomposition of rice husk started at about $250^{\circ}C,$ followed by relatively fast combustion of combustible gas until the temperature rose to $350^{\circ}C.$ After $350^{\circ}C,$ combustion of the carbon component proceeded relatively slowly as the temperature increased. Therefore, the ignition temperature of the rice husk could be estimated around $300^{\circ}C$. Crystallization of $SiO_2$ in the rice husk ash was found from the combustion temperature of $750^{\circ}C$ and became distinctly when the combustion temperature exceeded $900^{\circ}C$. The ash became darker with $SiO_2$ crystallization.

• The Journal of the Acoustical Society of Korea
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• v.42 no.3
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• pp.262-269
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• 2023

In this paper, we propose a Linear Prediction (LP) analysis-based feature for detecting Snapping Shrimp (SS) Noise (SSN) in underwater acoustic data. SS is a species that creates high amplitude signals in shallow, warm waters, and its frequent and loud sound is a major source of noise. The proposed feature takes advantage of the characteristic of SSN, which is sudden and rapidly disappearing, by using LP analysis to detect the exact noise interval and reduce the effects of SSN. The error between the predicted and measured value is large and results in effective SSN detection. To further improve performance, a constant false alarm rate detector is incorporated into the proposed feature. Our evaluation shows that the proposed methods outperform the state-of-the-art MultiLayer-Wavelet Packet Decomposition (ML-WPD) in terms of receiver operating characteristic curve and Area Under the Curve (AUC), with the LP analysis-based feature achieving a higher AUC by 0.12 on average and lower computational complexity.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.57-65
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• 2010

In this paper, we present a universal steganalysis scheme. The proposed method extract features of two types. First feature set is extracted from histogram characteristic of the wavelet subbands. Second feature set is determined by statistical moments of wavelet characteristic functions. 3-level wavelet decomposition is performed for stego image and cover image using the Haar wavelet basis. We extract one features from 9 high frequency subbands of 12 subbands. The number of second features is 39. We use total 48 features for steganalysis. Multi layer perceptron(MLP) is applied as classifier to distinguish between cover images and stego images. To evaluate the proposed steganalysis method, we use the CorelDraw image database. We test the performance of our proposed steganalysis method over LSB method, spread spectrum data hiding method, blind spread spectrum data hiding method and F5 data hiding method. The proposed method outperforms the previous methods in sensitivity, specificity, error rate and area under ROC curve, etc.

• Journal of the Korean Society of Costume
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• v.40
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• pp.137-147
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• 1998

Fahion as the form construction of decon-structivistic architecture was analyzed by dividing it into the intrinsic aspect and the formal aspect through an introduction of three characteristic architectural principles into fashion. Intrinsic deconstructivistic fashion as the construction of architectural form has the mixurte of genders both in a form of transvestic and in a form of genderless look as dualism, and can be characterized by pluralistic nationlism with the emergence of the Third World alienated from the international society, and so forth. Difference and the prefixes of dis-and de- are schizophrenic mystic illusionism, chance effect and the differance of space and time and is supporting Jacques Derrida's chiasmus that is the perspective of collage in painting and the multiple observation of collage in painting and the multiple observation point as the play of borrowing the surrealistic technique. The formal construction of deconstructivistic fashion the construction of architectural form has intertextuality material, hybridization of items and the blending of modes and another sphere. Trace as icon deconstrucion attains historical analysis. Dis and de in fashion are showing the retrogre-ssion of gravity through decomposition, decon-tinuity and disjunction emerge nonstructural silho-uette, juxtaposition, inversion and replace- ment of underwear and outer garments. Their decentring expression emerged as construction through mixture and repetition as well as overlapping of planes or spaces. And their disjuctive representation appeared in the form of mutual juxtaposition and substitution with the double-side of formal construction in functional terms.

• Textile Coloration and Finishing
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• v.8 no.2
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• pp.16-24
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• 1996

Polyester microfiber fabrics were alcoholysed at 120, 140, and 16$0^{\circ}C$ in 0.5, 1.0, and 1.5% of sodiumglycerolate/glycerol solutions(NaGR) up to 80% and the characteristic decomposition features were compared and discussed with the results of the hydrolysis done by 5% sodium hydroxide solution(NaOH) at 80, 90, and 10$0^{\circ}C$. The resulting activation thermodynamic parameters calculated by the combined use of the Arrhenius equation and the Eyring equation were in NaOH case ${\Delta}H^*$=- 13.89 kcal/mol, ${\Delta}S^*$/=-38.12 cal/mol K, and ${\Delta}G^*$=25.25 kcal/mol and in NaGR case ${\Delta}H^*$=29.81 kcal/mol, ${\Delta}S^*$=-2.29 cal/mol K and ${\Delta}G^*$=30.49 kcal/mol. Since in all cases NaGR-PET system has higher activation thermodynamic parameters, it was concluded that NaGR-PET reaction system is more favorable at high temperatures and occurs in a less selective fashion, in comparison to the NaOH-PET reaction system.

• Journal of environmental and Sanitary engineering
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• v.18 no.3 s.49
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• pp.48-58
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• 2003

To obtain the preliminary design data for combustion of paper sludges, decomposition characteristics and combustion kinetics of paper sludges reactor have been determined in a TGA reactor. Also, the combustion characteristics of paper sludges have been determined in a fluidized bed reactor. The data obtained from the TGA reactor indicate that dewatering of paper sludge is terminated at temperature below 130${\circ}$C. With heating rate of 20${\circ}$C/min, combustion is terminated at temperature below 340${\circ}$C .The combustion rate is found to be first order with respect to temperature and oxygen concentration. Activation energies for paper wastes are found to be 570, 700, 2600, 4600 Kcal/mole, respectively. The calcination conversions were investigated with the operating temperature and residence time. In this investigation, it was found that calcination conversion was affected by the operating temperature and residence time. The optimum conditions of operating temperature and mean residence time were 850${\circ}$C and 6 minutes of respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1080-1083
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• 2002

In this paper, we have studied with regard to the use of lasers for modifying the surface properties of silicon in order to improve it's wettability and adhesion characteristics. Using an Nd:YAG pulse laser, the wettability and adhesion characteristics of silicon surface have been developed by an Nd:YAG pulse laser. It was found that the laser treatment of silicon surfaces modified the surface energy. In the result of wetting experiments, by the sessile drop technique using the distilled water, wetting characteristic of silicon after the laser irradiation shows a decreased value of the contact angle. In case of the laser treated silicon surface, laser direct writing of copper lines has been achieved by pyrolytic decomposition of copper formate films$(Cu(HCOO)_2{\cdot}4H_2Q)$, using a focused $Ar^+$ laser beam$(\lambda=514.5nm)$ on the silicon substrates. The deposited patterns were measured by energy dispersive X-ray(EDX), Scanning Electron Microscopy(SEM) and surface profiler($\alpha$-step) to examine the cross section of deposited copper lines and linewidth.