• Bulletin of the Korean Chemical Society
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• v.23 no.1
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• pp.48-52
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• 2002

Using several molecular modeling programs we have performed computer simulations to investigate the complexation behaviors of an ester derivative of p-tert-butylcalix[5]arene (1e) toward a variety of butylammonium ions. Semi-empirical AM1 method was used for calculating the binding energies and the formation enthalpies. MM and CVFF forcefields for molecular mechanics calculations were adapted to express the complexation energies of the host. Molecular dynamics were performed to the calculated complex systems to simulate the ionophoric behavior of the host-guest complexes. The absolute Gibbs free energies of the host (1e) complexed with four kinds of butylammonium ions have been calculated using the Finite Difference Thermodynamic Integration (FDTI) method in Discover. Calculation results show that the trend in complex formation is n-$BuNH_3^+$ > iso-$BuNH_3^+$ >> sec-$BuNH_3^+$ > tert-$BuNH_3^+$, which is in good agreement with the experimental results.

• Bulletin of the Korean Chemical Society
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• v.14 no.5
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• pp.631-635
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• 1993

The polarizability and the transition state energy of a cephalosporin are assumed to be theoretical indices of the permeability through the outer membrane and of reactivity of ${\beta}$ -lactam ring with penicillin binding proteins, respectively, in Gram-negative bacteria. They are computed by AM1 method and used as variables of quantitative structure-activity relationship study. The results justify quadratic dependence of the activity on the variables. The intersection of difference volumes between $\beta-lactamase$ stable cephalosporins and unstable ones manifests that the steric hindrance of 7-side chain is responsible for the ${\beta}$ -lactamase stability.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.1-8
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• 2016

PURPOSES : This study evaluates the reliability of the patterns of changes in the road surface temperature during winter using a statistical technique. In addition, a flexible road segmentation method is developed based on the collected road surface temperature data. METHODS : To collect and analyze the data, a thermal mapping system that could be attached to a survey vehicle along with various other sensors was employed. We first selected the test route based on the date and the weather and topographical conditions, since these factors affect the patterns of changes in the road surface temperature. Each route was surveyed a total of 10 times on a round-trip basis at the same times (5 AM to 6 AM). A correlation analysis was performed to identify whether the weather conditions reported for the survey dates were consistent with the actual conditions. In addition, we developed a method for dividing the road into sections based on the consecutive changes in the road surface temperature for use in future applications. Specifically, in this method, the road surface temperature data collected using the thermal mapping system was compared continuously with the average values for the various road sections, and the road was divided into sections based on the temperature. RESULTS : The results showed that the comparison of the reported and actual weather conditions and the standard deviation in the observed road surface temperatures could produce a good indicator of the reliability of the patterns of the changes in the road surface temperature. CONCLUSIONS : This research shows how road surface temperature data can be evaluated using a statistical technique. It also confirms that roads should be segmented based on the changes in the temperature and not using a uniform segmentation method.

• Journal of Korean Physical Therapy Science
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• v.10 no.2
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• pp.73-85
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• 2003

The purpose of the present study was to the investigate the effect of sports massage, kaltenborn-evjenth orthopedic manipulative therapy and electrical therapy, general exercise on the limitation of range of motion(ROM) and on the pain(VAS) in patients with frozen shoulder. Fiftheen frozen shoulder patients between 50 and 60 years of age(females) were selected and were divided equally by random distribution into A group(sports massage, kaltenborn-evjenth orthopedic manipulative therapy, N=7)and B(electrical therapy, general exercise therapy, N=7) group. The results obtained were as follows : 1) The range of motion between two groups are significantly different in the treatment times, the ROM of A group increase in after-treatment(2 week 4 week) in comparison with ROM in before-treatment, it is significant increase. And it is significant difference in B group. 2) The pain level between two groups are not significantly different in the treatment times, the pain level of A group decrease in after-treatment(2 week, 4 week) in comparison with before-treatment, it is significant decrease. And it is significant difference in B group. Although the pain level of the A group decrease in after 2 week treatment in comparison with before-treatment but it is not significant decrease. Although the pain level of the B group decrease in after 4 week treatment in comparison with after 2 week treatment, but it is not significant decrease. 3) The A group is more effective in increasing the ROM and decreasing the pain level than B group during treatment times. The results showed that both A group method and B group method are effective ROM increase and pain reduce, but A group method is superior to B group method in ROM increase and pain reduce.

• Journal of Korea Spatial Information System Society
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• v.1 no.1 s.1
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• pp.49-55
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• 1999

Extracting information of maps is necessary to establish the GIS. In this paper, a house recognition method on the scanned topographic map is described. A contour detection method is used to extract houses from the scanned maps and RLE (run-length encoding) method is used for manipulating houses touching grid lines. To handle houses touched to roads and borderlines, morphological operation is used. To remove misrecognition occurred by morphological operation, the legions which contain characters on the map are also automatically eliminated.

• Journal of the Ergonomics Society of Korea
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• v.21 no.1
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• pp.51-65
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• 2002

As the method of providing information is getting multimedia, the synthetic voice is used in not only CTI(Computer Telephony Integration), information service for the blind, but also applications on internet. But properties of synthetic voice, such as speech rate, pitch, timbre and so on, are not adjusted to customers' preference but providers' preference. In order to consider customers' preference, this study proposed four subjective factors of voice through the evaluation of voice using the method of sensibility ergonomics. And the relation synthetic voice to be agreeable to the ear with emotional images was formulated as a fuzzy model. Consequently, this study proposed the speech rate and pitch of synthetic voice which is agreeable to the ear.

• Journal of Welding and Joining
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• v.34 no.4
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• pp.1-8
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• 2016

Metal AM(Additive Manufacturing) has been steadily developed and that is classified into two method. PBF(Powder Bed Fusion) deposited in the bed by the laser or electron beam as a heat source of the powder material and DED(Directed Energy Deposition) deposited by varied heat source of powder and solid filler material. In the developed countries has been applying high productivity process of solid filler metal based DED method to the aerospace and defense sectors. The price of the powder material is quite expensive compared to the solid filler metal. A study on DED method that is based on a solid filler metal is increasing significantly although was low accuracy and degree of freedom.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.140-144
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• 2018

Isotopic analyses of plutonium and low-enriched uranium mixtures with particle sizes of $0.6-3.3{\mu}m$ were performed using thermal ionization mass spectrometry with a continuous heating method to verify its effectiveness for the accurate analysis of minor isotopes without sample pretreatment. The mixed particles used in this study were prepared from a mixed solution of plutonium (SRM 947) and uranium (U010, $^{235}U$ 1% enriched) reference materials. The isotope ratios for plutonium in the individual mixed particles, including $^{238}Pu/^{239}Pu$, $^{241}Pu/^{239}Pu$ as well as $^{240}Pu/^{239}Pu$, and $^{242}Pu/^{239}Pu$, were in good agreement with the certified values despite the isobaric interference of $^{238}U$ and $^{241}Am$. The isotope ratios for uranium in the mixed particles also agreed well with the certified values within the range of error. However, the isotope ratios for minor isotopes, such as $^{234}U$ and $^{236}U$, in the particles with diameters of less than approximately $1.8{\mu}m$ could not be measured because numbers of $^{234}U$ and $^{236}U$ atoms in analyzed particles are too low. These results indicate that thermal ionization mass spectrometry with a continuous heating method is applicable for the analysis of trace amounts of plutonium isotopes, including $^{238}Pu$ and $^{241}Pu$, despite the presence of the respective isobars $^{238}U$ and $^{241}Am$ in the microsamples.

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.62-67
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• 1993

The microscopic origin of nonlinear optical properties of quinoline derivatives have been investigated theoretically using MOPAC-AM1 method. In order to prepare promising nonlinear optical active polymers of polyquinoline derivatives, the optimized positions of strong electron donor and electron acceptor are determined in the heterocyclic ring for the energetically favorable structures. For each compound, the effect of the substituted positions on the microscopic nonlinear coefficients were investigated. Polyquinoline was already evaluated to have outstanding physical and mechanical properties so that its monomeric analogues were designed and synthesized for developing new second and third order nonlinear optical main chain polymers. Using the MOPAC-AM1 method, properties calculated include the intrinsic ground-state dipole moments, the polarizabilities, first and second hyperpolarizabilities under the condition of finite-field $(\omega$ = 0).

• Journal of IKEEE
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• v.23 no.2
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• pp.454-460
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• 2019

In this paper, a watt-level 2.4-GHz RFCMOS linear power amplifier (PA) with pre-distortion method using variable capacitance with respect to input power is demonstrated. The proposed structure is composed of a power detector and a MOS capacitor to improve the linearity of the PA. The pre-distortion based linearizer is embedded in the two-stage PA to compensate for the gain compression in the amplifier stages, it also improves the output P1dB by approximately 1 dB. The simulation results demonstrate a 1-dB gain compression power of 30.81 dBm at 2.4-GHz, and PAE is 29.24 % at the output P1dB point.