• Tunnel and Underground Space
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• v.22 no.5
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• pp.339-345
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• 2012

Information on the deformation behavior and fracture strength of rocks subjected to dynamic loadings is important to stability analyses of underground openings underground vibration due to rock blasts, earthquakes and rock bursts. In this study, Split Hopkinson Pressure Bar (SHPB) system was applied to estimate dynamic compressive and tensile fracture strengths of limestone and also examine deformation behavior of limestones under dynamic loadings. A micro-focus X-ray CT scanner was used to observe non-destructively inside the impacted limestone specimens. From the dynamic tests, it was revealed that the limestone have over 140MPa dynamic compressive strength and the strain-rate dependency of the strength. Dynamic Brazilian tensile strength of the limestone exceeds 21MPa and shows over 3 times static Brazilian tensile strength.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.1 s.343
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• pp.33-40
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• 2006

This paper presents a novel surface acoustic wave (SAW)-based pressure sensor, which is composed of single phase unidirectional transducer (SPUDT), three reflectors, and a deep etched substrate for bonding underneath the diaphragm. Using the coupling of modes (COM) theory, the SAW device was simulated, and the optimized design parameters were extracted. Finite Element Methods (FEM) was utilized to calculate the bending and stress/strain distribution on the diaphragm under a given pressure. Using extracted optimal design parameters, a 440 MHz reflective delay line on 41o YX LiNbO3 was developed. High S/N ratio, shan reflection peaks, and small spurious peaks were observed. The measured S11 results showed a good agreement with simulated results obtained from coupling-of-modes (COM) modeling and Finite Element Method (FEM) analysis.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.267-276
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• 2010

The purpose of this study was to investigate the variations in gait parameters according to arm slings used in healthy adults. Twenty healthy adults (9 males, 11 females) participated in this study and walked at self-selected speeds on a GAITRite-instrumented carpet. They were randomly assigned conditions: without an arm sling, a care sling, a Harris hemi arm sling, a CVA sling, and a Rolyan humeral cuff sling. The following gait parameters were analyzed: the temporo-spatial parameters of gait velocity, swing phase, single support, cadence. In the comparison of parameters in each trial, step length was statistically significantly changed(p=.002). The right step length was significantly decreased in the Harris hemi arm sling and increased in the Rolyan humeral cuff sling when compared with no sling. This study found that several different types arm slings varied gait pattern in healthy adults.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.173-178
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• 1985

Extracellular amylase from tile filtrate of the submerged culture of Ganoderma lucidum was partially purified by ammonium sulfate precipitation and its properties were studied. The optimum pH and temperature of the enzyme activity were 5.5 and 5$0^{\circ}C$. respectively. This enzyme was most stable at pH 5.0 and stable up to 3$0^{\circ}C$, but it lost completely the activity when it was treated at 6$0^{\circ}C$ for 10 min. The enzyme was activated by the addition of M $n^{++}$, $C^{++}$ and C $u^{++}$, but inhibited by H $g^{++}$, A $g^{++}$ And various enzyme inhibitors and chemical reagents did not affect the enzyme activity. The enzyme hydrolyzed the boiled amylaceous polysaccharides, but it hydrolyzed raw starches very slowly. The activation energy of the enzyme for soluble starch was calculated and found to be 7.06 Kcal per mole. The Km values of the enzyme for soluble starch, amylose, amylopectin and glycogen were 0.16, 0.37, 0.19, and 0.16mg/$m\ell$, respectively. Maltose was found to inhibit the enzyme activity and kinetic analysis revealed a competitive type of inhibition.n.n.n.n.n.

• Journal of Advanced Navigation Technology
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• v.18 no.4
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• pp.393-400
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• 2014

With developed countries, nationally the supply and development of electric vehicle(EV) has been going at a rapid pace. Now, the charger specifications, charging methods and standardization of communication protocols is going in each country and a lot of company are involved in the business about those. To popularize it as existing car, it is required to build the network and infrastructure which is proper for domestic environment. It should also need to be able to develop standardized protocols can be beyond the construction of the protocol of the upper stage server and charger, and is used in a residential environment actually applied to related industries. Therefore, in this paper, we propose a home network model of EV that raised the need for a study of the charging system for EV, using M2M technology and multi-charging system tailored to the residential environment of our country.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.243-246
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• 2008

This thesis suggests block cipher operating mode using ASR(Arithmetic Shift Register). ASR is ratted arithmetic shift register which is sequence that is not 0 but initial value $A_0$ multiplies not 0 or 1 but free number D on $GF(2^n)$. This thesis proposes ASR mode which changes output multiplying d and Floating ASR mode which has same function but having strengthened stability altering d. If we use ASR's output as a counter, there's advantage that it has higher stability and better speed than CTR. Also, ASR mode and FASR mode have advantage of Random access which is not being functioned on CTR mode, they can be widely used to any part which Random access is needed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.11
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• pp.1148-1161
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• 2012

Recently, developments in the field of communication and network technologies induced new paradigm in the defense weapon system. As a consequence, military authorities develop the Tactical Information Communication Network(TICN) system to adapt to the changing paradigm. One of the most important functions of TICN is real-time communication. As a result, TICN system needs to receive real-time information from the battlefield, and the key technology to support these features is MANET(Mobile Ad-Hoc Network) routing protocol. In this paper, we analyze problems of the shortest path scheme in tactical Ad-Hoc networks, which is widely used in common Ad-Hoc networks. We propose efficient routing protocol for tactical MANET by considering the environment of small combat units, such as node position, speed and data size. The proposed algorithm shows reliable data transfer and low latency in battlefield.

• Economic and Environmental Geology
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• v.37 no.5
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• pp.509-519
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• 2004

The ground subsidence that occurred in the abandoned coal mining area, Gaeun, Korea, was observed using 25 JERS-1 SAR interferograms from November 1992 to October 1998. We carried out measurements on a subset of image pixels corresponding to point-wise stable reflectors(PS: permanent scatterer) by exploiting a long temporal series of interferometric phases and compared it with the distribution map of in situ examined crack level. PSs could be identified by means of amplitude dispersion index and coherence of the interferograms and the density of PS was much higher in an urban area than in a mountainous region. The measured subsidence rate represented the average velocity in a period of image acquisition and excluded complex nonlinear displacements such as an abrupt collapse. The mean line-of-sight velocity in the study area is 0.19cm/yr and the estimation error is 0.18cm/yr. The center of the abandoned Gaeun coal mine(0.49cm/yr) and the area opposite Gaeun station(1.66cm/yr) were observed as the most highly subsiding areas.

• Analytical Science and Technology
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• v.15 no.2
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• pp.163-171
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• 2002

The adsorption characteristics of Cd(II) and Pb(II) ions has been studied by using chitin as an adsorbent. The pure chitin was obtained from the extraction of red-crab shell dumped by fish factory. Adsorption kinetics of Cd(II) and Pb(II) ions on the chitin reached at the maximum adsorption within two minutes. Adsorbed amounts of heavy metals were pH 7.0>10.5>3.5 in the following order. Adsorption ratio by chitin was 21${\sim}$99% for Cd(II) ion and 24${\sim}$95% for Pb(II) ion. Recovery ratio of Cd(II) ion on the chitin was 22${\sim}$53%, and that of Pb(II) ion was 22${\sim}$73%. The adsorption behavior of these heavy metals was explained well by Freundlich adsorption isotherm.

• Journal of Preventive Medicine and Public Health
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• v.24 no.4 s.36
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• pp.507-515
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• 1991

One, two, six and ten week old Sprague-Dawley rats were exposed to carbon monoxide at 3,700 ppm for 30 minutes, and carboxyhemoglobin was measured immediateley. 5, 30, 60, 90, 120 minutes after the exposure. In each time after the exposure, the means of the carboxyhemoglobin levels were compared among the week age groups. The regression analysis was done using the natural logarithm of the carboxyhemoglobin concentration as a dependent variable and the time after the exposure as an independent vaiable. From the regression equation, the half lives of the carboxyhemoglobin were calculated. The one week old rats showed significantly higher carboxyhemoglobin level than other week age rats in the entire time after the exposure. The corrected carboxyhemoglobin concentration calculated by subtracting the normal carboxyhemoglobin level from the measured carboxyhemoglobin at each age group, showed no uniform differences.