• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.22-28
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• 2013

In this paper, new LBS (location based service) are proposed using conventional DMB (digital multimedia/mobile broadcasting) system. LBS applications are proposed that can be suitable for the subway and ground transportation based on S-DMB (satellite-DMB) and T-DMB (terrestrial-DMB) respectively. In the shaded area such as subway, the broadcasting signal transmitted from the satellite of S-DMB system should be retransmitted by the earth repeater called the gap filler and each gap filler has its own identification value called the gap filler ID which introduces the area in which the gap filler was installed. Therefore, the LBS can be implemented by using the gap filler ID of S-DMB on the subway in which the GPS (global positioning system) can't be received. Unlike the LBS on the subway, the combination of T-DMB and DGPS (differential GPS) will be introduced as a way for ground transportation. Generally, DGPS has been designed to compensate the position value calculated from the GPS signal so that positioning error of about 1 meter can be obtained by using DGPS information. T-DMB system transmitting DGPS signal will be expected to be commercial in Korea and, if using DGPS information transmitted through T-DMB network, LBS with more precise positioning than GPS alone can be implemented in the ground vehicles.

• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.673-680
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• 2019

GAP or GAP-co-BO based energetic thermoplastic elastomers (ETPEs) were synthesized by changing the hard segment content percent in the range of 30~45% by 5% difference. Thermal and mechanical properties of GAP-co-BO based ETPEs were compared to those of GAP based ETPEs. FT-IR results showed that the capability of forming hydrogen bond increases with increasing the hard segment content in GAP/GAP-co-BO based ETPE, and also the GAP-co-BO based ETPEs are stronger than GAP based ETPEs in the hydrogen bond formation. DSC and DMA results showed that the glass transition temperature (T_g) of GAP based ETPEs increased with the increment of the hard segment content, while the T_g of GAP-co-BO based ETPEs was maintained even the hard segment content increased. The storage modulus at room temperature of the GAP-co-BO based ETPEs was higher than that of the GAP based ETPEs. This was due to the strong phase separation behavior of the hard and soft segment of GAP-co-BO based ETPEs, which further resulted in the stronger breaking strength and lower tensile elongation at break point for GAP-co-BO based ETPE than the GAP based one.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.4
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• pp.107-115
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• 2011

Since 2009 The Korean National Police Agency has been pushed "permissive left-turn" forward in order to making progress in Korean traffic operations system. Preceding researches manuals and guidelines present 6 standards(# of accidents # of lanes, pedestrian volume sight # of permissive left-turn lanes vehicle volume) as installation permissive left-turn. But in practical affairs it is most important that secure enough Gap-time between permissive left-turn vehicle and opposite through lane vehicle to make permissive left-turn vehicle move safer and more efficiently. This study suggests applying gap acceptance theory in microscopic model to permissive left-turn installation standards. Analysis methods of this study are field data survey statistical analysis and microscopic simulation analysis. This study collected field data by using AVI recording and measured permissive left-turn vehicle intersection passing time(T1) and against the opposite through lane vehicle Gap-time(T2). And statistical analysis performed about two values that measured before to predict the functionality between T1 and T2. These studies to overcome the limit of sample size carried out a microscopic simulation(VISSIM) plan and collect more samples to input statistical analysis.

• Journal of dental hygiene science
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• v.11 no.5
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• pp.463-469
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• 2011

The purpose of this study was to investigate effect of gap between expected job and performed job on job satisfaction and turnover intention in clinical dental hygienists. A total 292 hygienist in dental hospitals and dental offices in nationwide completed a questionnaire on their daily routine job and job which they expected and measured gap between expected job and performed job, such as chairside assisting, preventive care, consultation, reception. The study showed the gap on chairside assisting job among age, career and showed the gap on consultation among age, education, career and showed the gap on reception among age, career. gap on chairside assisting, salary satisfaction, personal day affected job satisfaction and gap on chairside assisting, children, salary satisfaction affected turnover intention. The study showed that salary satisfaction and gap on chairside assisting associated with turnover intention and job satisfaction. Personal day affected job satisfaction but did not affect turnover intention.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1915-1918
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• 2002

본 논문에서는 non-radiative dielectric (NRD) guide를 이용한 듀플렉서를 설계하였다. 설계된 듀플렉스는 두 개의 gap-coupled 필터와 T-junction으로 구성되어 있다. Gap-coupled 필터의 설계에는 차단 주파수 영역 등가회로를 이용하였으며 T-junction은 30dB 이상의 반사손실을 갖도록 최적화하여 두 가지의 형태로 설계하였다 위의 설계과정을 통하여 1% 대역폭, 0.1dB ripple, 37.7 및 38.3 GHz의 중심주 파수를 갖는 듀플렉서를 설계하였다. 두 가지 형태의 결합부를 갖는 듀플렉서에 대해 시뮬레이션하여 응답특성을 비교한 결과 듀플렉서의 응답특성이 원하는 결과에 근접하게 나옴을 확인하였다.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.273-282
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• 2011

This study was to investigate the effect of improve forelimb sensorimotor function and neurotrophic factor(GAP-43) expression when differing an application time of tDCS in ischemic brain injury rat model(pre, $1^{st}$, $7^{th}$, $14^{th}$). Focal ischemic brain injury was induced in 80 Sprague-Dawley rats through middle cerebral artery occlusion(MCAO) by 'Longa' method. And then experimental groups were randomly divided into four groups; GroupI: MCAO induction, GroupII: application of tDCS(10 min) after MCAO induction, GroupIII: application of tDCS(20 min) after MCAO induction, GroupIV: application of tDCS(30 min) after MCAO induction. Modified limb placing test and single pellet reaching test were performed to test forelimb sensorimotor function. And the histological examination was also observed through the immunohistochemistric response of GAP-43(growth-associated protein-43) in the cerebral cortex. In modified limb placing test, groupIII(p<0.05) showed significantly improve than the other groups on $14^{th}$). day. In single pellet reaching test, groupIII(p<0.01) and groupIV(p<0.05) significantly improved on $14^{th}$) day. And in immunohistochemistric response of GAP-43, group III showed significantly positive response than the other groups on $14^{th}$ day. These results suggest that the intensity(0.1 mA)/time(20 min) condition of tDCS application has a significant impact on the sensorimotor functional recovery in focal ischemic brain injury rat models.

• Journal of Welding and Joining
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• v.14 no.1
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• pp.82-91
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• 1996

The maximum butt-joint gap size in $CO_2$ laser beam welding of SAPH steel plates with different thicknesses and its bending formability were studied. In the range of the gap size$\geq$0.1mm, the optimal butt welding speed was faster than that of no gap (air gap) condition. This behaviour was independent on the difference of thickness at any combination. Also, the allowable gap size in steel plates with different thicknesses was larger than with same thicknesses. In the range of $T/T_0$(bead shape) $\geq$ 0.8, good bending formability was obtained at any combination of thickness. The formability was improved by reducing the hardness in weld bead using pre-heating process. Finally, FEM result of the laser beam welded underframe with different thicknesses was compared to that of the conventional spot welded underframe.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.46-46
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• 2009

The photoconductive $AgGaSe_2$(AGS) layers were grown by the hot wall epitaxy method. The AGS layer was confirmed to be the epitaxially grown layer along the <112> direction onto the GaAs(100) substrate. The band-gap variation as a function of temperature on AGS was well fitted by $E_8(T)=1.9501-8.37{\times}10^{-4}T^2/(T+224)$. The band-gap energy of AGS obtained at 293 K was determined to be 1.8111 eV.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.1
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• pp.15-20
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• 2004

This paper discusses electrical insulation characteristics at cryogenic temperature, especially focusing on partial discharge (PD) inception characteristics, for high temperature superconducting cables. In liquid nitrogen (L$N_2$) / polypropylene (PP) laminated paper composite insulation system, PD inception strength (PDIE) was evaluated in terms of volume effect and V-t characteristics. Different kinds of butt gap condition were applied in the experiments, using parallel plane and coaxial cylindrical cable samples. Experimental results revealed that the volume effect on PDIE could be evaluated by the statistical stressed liquid volume (SSLV) taking account the discharge probability not only in the butt gap but also in the other thin layers between PP laminated papers. Furthermore, the indices n of V-t characteristics at PD inception were estimated to be 80∼110, irrespective of the butt gap condition.

• Journal of Photoscience
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• v.7 no.2
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• pp.67-71
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• 2000

A quantum-chemical investigation on the conformations and electronic properties of trans(diphenyl-diheterocyclic) ethenes(t-PHEs) as building block for fully $\pi$-conjuated polymer are performed in order to display the effects of heterocyclic ring substitution. Structures for the molecules, t-PHEs were fully optimized by using semiempirical AM1, PM3 methods, and ab initio HF methods, with 6-31G basic set. The potential energy curves with respect to the change of single are obtained by using ab initio HF/6-31G basic set. The curves are not similar shapes in the molecules with respect to heterocyclic rings. It is shown that the steric repulsion interactions between phenyl ring and heterocyclic ring are subjected to different type with the respect to each heterocyclic ring. Electronic properties of the molecules were molecules were obtained by applying the optimized structures and selected geometries to the extended Huckel method. To investigate the change of HOMO-LUMO gap with respedt to the torsion angle, we select the optimized structures. By using the results, the dependency of conjugation for the energy gaps is analyzed. For t-PHE the energy gap increase up to 0.52 eV compared with its planar structure. In the cases of t-PHE and t-PHE, the energy gap increase by 1.29 and 1.15 eV, respectively, compared with its planar structure.