• Journal of the Korean Geotechnical Society
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• v.28 no.9
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• pp.97-106
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• 2012

In order to investigate mechanics of mixtures composed of sand and non-plastic silt, various specimens, with sand dominating the soil structure, and with varying fines content, fines content varying were produced. Isotropic consolidation tests were performed using high pressure triaxial test apparatus within high pressure levels where sand grain crushing happened. Experimental results showed that compressive curve of sand after yielding contracts to the NCL due to breakage of sand grains. Moreover, with the increase of fines content, coarse grains are surrounded by fines to form cushion effect, which made the breakage of coarse grains become difficult. Therefore, the maximum inclination of compressive curve became flatter and yield stress increased.

• Korean Journal of Clinical Pharmacy
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• v.8 no.1
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• pp.1-12
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• 1998

Rheumatoid arthritis (RA) is a common systemic inflammatory disease which DMARDS have been widely used as a treatment modality both as monotherapy and combination therapy Bucillamine, one of newer DMARDS, has recently proven its efficacy as monotherapy in the treatment of RA. The objective of this study was to compare the efficacy and the safety of bucillamine monotherapy and bucillamine plus methotrexate combination therapy in the treatment of rheumatoid arthritis. Forty-nine mild RA patients were enrolled in this prospective, open-trial and were assigned to receive bucillamine 200 mg/day (n=18) or bucillamine 200 mg/day and methotrexate 7.5-15 mg/week (n=31) orally for 16 weeks. Concomitant use of NSAID and prednisolone <5 mg/day or equivalent dose of steroid were allowed. Both monotherapy group and combination therapy group have shown significant improvement in disease activities (Ritchie index, painful joints, swollen joints, morning stiffness, grip strength, ESR, RF, CRP, patient's self assessment of pain, physician's global assessment of disease activity) from the baseline. However, there was no statistically significant difference between two groups. The adverse effects were more frequently shown in combination therapy group than monotherapy group. In conclusion, in patients with mild RA monotherapy has shown to be equally efficacious as combination therapy with less side effects.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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• pp.575-582
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• 2000

The Electrical conduction and optical properties of Ta$_{2}$/O$_{5}$ thin films as the insulators in DRAM capacitors were studied. Liquid Ta/sib 2//O sub 5/ were prepared by a sol-gel processing and multiple layers were applied by spin-coating up to thickness of 800$\AA$. At annealing temperature of 300~$600^{\circ}C$ the electrical conduction and specific dielectric constant were discussed the behaivor of carrier were observed by the Thermally Stimulated Current (TSC) at the temperature range of 30~23$0^{\circ}C$. At annealing temperature of 300~$600^{\circ}C$ the samples were found to be amorphous below $600^{\circ}C$ and crystalline over it. The electrical strength was about 2.2 MV/cm at 40$0^{\circ}C$. In spite of noncrystallization over 50$0^{\circ}C$ the increasing of leakage current due to pinholes and increasing creak. The refractive index was obtained maximum (2.2) at 40$0^{\circ}C$. The dielectric constant was obtained maximum(18.6) at 40$0^{\circ}C$. TSC was observed one peak at the temperature range of 30~23$0^{\circ}C$ from sample at 40$0^{\circ}C$. In the case of collecting voltage the peak size is decreased in proportion to collecting voltage and then the peak may be thought carrier to be a ionic space charge.e.

• Journal of Korea Foundry Society
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• v.22 no.3
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• pp.121-129
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• 2002

According to the investigation of waste $CO_2$ molding sand in the 15 steel foundries in Busan and Gyeong area, about 1 ton of waste $CO_2$ molding sand per ton of steel castings production was produced In order to reduce amount of $Na_2O$, Loss of Boiling (L.O.B), Loss of Ignition (L.O.I), Conductivity and PH which are present in the waste $CO_2$ molding sand below the reclamation effect, more than 50% of elimination for reclamation was required. It was found that the waste $CO_2$ molding sand does not contain a harmful component designated by industrial waste materials. Reclamation of the waste $CO_2$ molding sand was practically achieved by an abrasive-dry reclamation process. According to bench time of the sodium silicate-bonded $CO_2$ molding sand, reduction of compressive strength and surface stability index(S.S.I) become slowdown. Therefore, the reclaimed sand could be allowed the reuse of molding sand in $CO_2$ molding process including core sand.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.53-56
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• 2004

The a-Si:H TFT using ferroelectric of SrTi $O_3$as a gate insulator is fabricated on glass. Dielectric characteristics of ferroelectric are superior to $SiO_2$and S $i_3$ $N_4$. Ferroelctric increases on-current, decreases thresh old voltage of TFT and also improves breakdown characteristics. The a-SiN:H has optical band gap of 2.61 eV, refractive index of 1.8~2.0 and resistivity of 10$^{13}$ - 10$^{15}$ $\Omega$cm, respectively. Insulating characteristics of ferroelectrics are excellent because dielectric constant of ferroelectric is about 60~100 and breakdown strength is over 1MV/cm. TFT using ferroelectric has channel length of 8~20${\mu}{\textrm}{m}$ and channel width of 80~200${\mu}{\textrm}{m}$. And it shows that drain current is 3.4$mutextrm{A}$ at 20 gate voltage, $I_{on}$ / $I_{off}$ is a ratio of 10$^{5}$ - 10$^{8}$ and $V_{th}$ is 4~5 volts, respectively. In the case of TFT without ferroelectric, it indicates that the drain current is 1.5 $mutextrm{A}$ at 20 gate voltage and $V_{th}$ is 5~6 volts. With the improvement of the ferroelectric thin film properties, the performance of TFT using this ferroelectric has advanced as a gate insulator fabrication technology is realized.zed.d.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.5945-5949
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• 2014

The rural population is aging and farmers need to aim for mass production. This study examined the work efficiency of clamping and protecting crops. Strong winds are a risk for damage, but there are no reports of studies of the geometric design problem for vegetation. The accuracy of the simulation to obtain a load applied to the actual support and index was examined. The model was selected according to its strength based on the reliability of the simulation. Also acts in force of 0.1N to 0.6N, which can withstand the force of 1.29N with the results of this thesis research. The fixed clamp fixing for agricultural crops designed as a support was examined. These results are expected to help shorten working hours, and improve the growth of crops and disaster prevention.

• The KIPS Transactions:PartD
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• v.16D no.5
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• pp.683-690
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• 2009

Social Networks which is composed of network with an individual in the center in a web support mutual-understanding of information by searching user profile and forming new link. Therefore, if we apply the Social Network which consists of web users who have similar immanent information to web search, we can improve efficiency of web search and satisfaction of web user about search results. In this paper, first, we make a Social Network using web users linked directly or indirectly. Next, we calculate Similarity among web users using their immanent information according to topics, and then reconstruct Social Network based on varying Similarity according to topics. Last, we compare Similarity with Search Pattern. As a result of this test, we can confirm a result that among users who have high relationship index, that is, who have strong link strength according to personal attributes have similar search pattern. If such fact is applied to search algorithm, it can be possible to improve search efficiency and reliability in personalized and social search.

• Journal of Korean Society of Steel Construction
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• v.19 no.2
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• pp.211-221
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• 2007

A structural reliability analysis of fatigue truck model for fatigue failure of highway steel bridges was performed by applying the Miner's fatigue damage rule expressed as a function of various random variables affecting fatigue damage. Among the variables, the statistical parameters for equivalent moment, impact factor, and loadometer were obtained by analyzing recently measured domestic traffic data, whereas the parameters on fatigue strength, girder distribution factor, and headway factor of the measured data available in the literature were used. The effects of various fatigue truck models, fatigue life, ADTT, fatigue detail category, loadometer, and gross vehicle weight of fatigue truck on the reliability index of fatigue damage were analyzed. It is expected that the analytical results presented herein can be used as a basic background material in the calibration of both fatigue design truck and fatigue load factor of LRFD specification.

• Journal of Korean Society of Steel Construction
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• v.19 no.4
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• pp.395-402
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• 2007

Probabilistic risk assessment was conducted on a hybrid cable-stayed bridge consisting of a steel-composite plate girder and a concrete girder with a long span, designed using the working stress design and strength design methods. The component reliabilities of the bridge's cables, pylons, girders, and steel-concrete conjunction were evaluated using the AFOSM(Advanced First Order Second Moment) algorithm and the simulation technique at the critical sections, based on the maximum axial force, shear, and positive and negative moments of the selected sections. For the analysis of system reliability, the hybrid cable-stayed bridge consisting of cables, pylons, and plate girders was modeled into combined failure modes, and for system reliability, the probabilities of failure and reliability index of the structural system were evaluated. Based on the results of this study, the critical failure modes of the hybrid cable-stayed bridge based on the bridge's structural characteristics are suggested, and the efficiency of the partial ETA technique for use in the risk assessment method was confirmed.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2013.11a
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• pp.28-29
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• 2013

We have been measuring $CH_4$ flux in a rice paddy in Gimje using the eddy covariance method since July 2011. In order to measure the fast fluctuations of $CH_4$ concentration, an innovative LI-7700 open-path laser spectrometer is used. This high-precision, low power, light weight, low maintenance sensor enables us to operate it on a continuous and long-term basis. One particular feature, among other things, is the self-cleaning lower mirror which decreases maintenance requirements while ensuring more robust, continuous, high-quality dataset. Its cleaning is initiated at user-specified time intervals or a signal strength threshold, and its status is recorded as a diagnostic index. We have noticed that the operation of LI-7700 at Gimje site is quite challenging particularly due to its frequent mirror cleaning requirement and the associated sensitivity of the instrument. In this presentation, we present some field observation data regarding the mirror cleaning and their analysis, thereby suggesting the pertinent operation options for high-quality, maximum data retrieval in the field.