• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.371-381
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• 1983

This study is aimed at identifying the economic effects of drainage improvement projects. The total area of poor drainage is equivalent to 170,000ha, 13% of the total area of paddy field in Korea. The development of poor drained paddy is an urgent problem considering the low rate of self-sufficiency of food grain and the limitation of farmer's income increase. Rapid development of Korean economy has brought labor shoriage in rural farming sector. Accordingly farm mechanization is an important agricultural policy to hike labor productivity and to save production costs of rice farming. The expected economic benefits of the drainage improvement project are derived from increasing land productivity, expanding double cropped area and farming the farm mechanization base in paddy fields. The economic and financial rate of return of the project are considered very important decision making criteria for project implementation by resource allocation. Therefore this study covered benefit and cost analysis of the sampled area, the estimated financial rate of returns in $Buy{\check{o}}$ and Jinsung are represented 15% and 51% respectively and the economic rate of returns in both project area are also showing 1% and 26% respectively. The rate of return of the projects has showed an outstanding variance according to the locational and natural characteristics of the project area. As showing the above economic rate of return, $Buy{\check{o}}$ is very low Jinsung is very high. But the financial rate of return of both projects are considered comparatively high. Cosequently, the drainage improvement projects should be promoted from the view point of farm income increase to make narrow the income gap between rural and urban incomes and farm mechanization to solve labor shortage in the rural area.

• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.453-464
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• 2011

Objectives : The purpose of the study is to gain some basic material for the improvement of dental clinics' homepages through a survey investigation, in which college students of Dental Hygiene Departments and Dental Hygienists in Kwangju and Cheollanamdo Province Methods : It conducted the self-reported questionnaire survey on the Recognition Degrees of the Dental Clinics' Homepages from May 26, 2010 to October 19 targeting 240 dental hygienists who are working for dental offices and 638 college students of Dental Hygiene Departments. Results : 1. It was asked whether they have visited dental homepages for the recent one year; 'yes' answers occupied 68.1%, double than 'no' answers. 2. It was asked how much they know services provided in dental homepages; The more respondents correctly answered that there exist all these services like general information service, visitor's book and bulletin board service, reservation service, dental information service, counseling service, and visual service. 3. All the respondents answered that the homepage of each dental clinic is closely related with the image of the clinic : freshmen showed 3.84, sophomore showed 4.03, juniors showed 4.03, and dental hygienists showed 3.88. 4. It was asked how much they know services provided in dental homepages; Are there the homepages for dental hygienists? Many of them answered that IT experts or businesses are managing the homepages in the technical respect(38.4%) and their use and general administration mainly belongs to dental hygienists(46.2%). Conclusions : It is necessary that through the studies of dental hygienists' interest and understanding on dental homepages we have to seek the development orientation of the technical management and the way of using them, and furthermore we have to know the thoughts of patients on dental homepages, who are users of the dental informations, and find the ways of improving medical services which the patients want.

• Corrosion Science and Technology
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• v.6 no.4
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• pp.206-210
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• 2007

Aerospace aluminum alloys such as Al alloy 2024-T3 and 7075-T6 are subject to localized corrosion due the existence of intermetallics containing Cu, Mg or Zn. Chromate is currently widely used in the aerospace industry as the corrosion inhibitor for these alloys. However, chromate needs to be replaced due to its strong carcinogenicity. In this study, an extensive pigment screening has been performed to find replacements for chromates. Different categories of inhibitors were evaluated by immersion tests, DC polarization tests and other methods. Phosphates, zinc salts, cerium salts, vanadates and benzotriazole were found to be effective inhibitors for AA7075. Among those inhibitors, zinc phosphate was found to be the most effective in our novel, silane-based, one-step aqueous primer system. The performance of this primer is comparable to that of currently used chromate primers in accelerated corrosion tests, while it is completely chromate-free and its VOC is about 80% less than that of current primers. Studies by SEM/EDS showed that the unique structure of the superprimer accounts for the strong anti-corrosion performance of the zinc phosphate pigment. The self-assembled stratified double-layer structure of the superprimer is characterized by a less-penetrable hydrophobic layer at the top and a hydrophilic layer accommodating the inhibitors underneath. The top layer functions as the physical barrier against water ingress, while the lower layer functions as a reservoirfor the inhibitor, which is leached out only if the coating is damaged by a scratch or scribe. The presence of a silane in the primer further improves the adhesion and anti-corrosion performance of the primer.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.1
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• pp.27-36
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• 2019

Purpose : The purpose of this study figures out how the biofeedback exercise combined with a Shaker exercise and a jaw-opening exercise affects the suprahyoid muscle activation of stroke with a swallowing disorder. Methods : The study period was from June, 2018 to September, 2018, to 45 patients who were suitable for selection criteria. Participants were divided into three groups: a visuoauditory biofeedback group (VABG), and a visual biofeedback group (VBG), and a self-exercise group (SG). The three groups were divided into the Shaker exercise and the jaw-opening exercise, and the biofeedback training by themselves. Three groups performed an intervention three times a day, five times a week, and four weeks long. Also, suprahyoid muscle activity was measured with a pre-test, a post-test and a follow-up test. Results : To know the suprahyoid muscle activity after the intervention, there were statistically significant differences between the pre-test and the post-intervention (p< .01). All three groups showed the improvement with the mean comparing followed by VABG, VBG and SG. Comparing between the post- test and the follow-up test, all three groups showed the reduction of suprahyoid muscle activity with the mean comparing, followed VABG, VBG and SG. Conclusion : It found that it was more effective when providing a double-sensory biofeedback than when training with a single-sensory biofeedback. Therefore, it is necessary to provide a multi-sensory input when applying the biofeedback in rehabilitation of the swallowing disorder.

• Polymer(Korea)
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• v.25 no.5
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• pp.719-727
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• 2001

Recently it was found that the charge carrier transport properties are significantly enhanced due to effective intermolecular $\pi$-orbital overlapping and low disorder of hopping sites caused by self-organization of liquid crystal molecules. In this study, the xerographic properties of a double-layer photoconductor doped with nematic liquid crystal, 4-pentyl-4'-cyanoterphenyl (5CT), as a charge-carrier transport material to enhance the charge-tarrier mobility were investigated. From the results of measured surface voltage properties for the photoconductor doped with various concentrations of liquid crystal, 5CT, the initial voltage was found to increase with the concentration of 5CT and the dark decay decreased with the concentration of 5CT. The highest sensitivity was obtained at a specific concentration, 40wt% 5CT. The fluorescence behavior of the carrier transport layer (CTL) was also investigated. It was found that the charge-carrier transport properties of the organic photoconductor depend on the charge-carrier transport properties of the complex. The TNF : 5CT (40 wt%) and OXD : 5CT (40 wt%)samples showed the highest sensitivity because the greatest charge transport complex was termed between the charge-carrier transport materials in these samples.

• Korean Journal of Crystallography
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• v.11 no.4
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• pp.212-223
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• 2000

A stochiometric mix of CuInTe₂ polycrystal was prepared in a honizonatal furnace. To obtain the single crystal thin films, CuInTe₂ mixed crystal was deposited on throughly etched GaAs(100) by the HWE system. The source and substrate temperatures were 610℃ and 450℃ respectively, and the thickness of the deposited single crystal thin film was 2.4㎛. CuInTe₂ single crystal thin film was proved to be the optimal growth condition when the excition emission spectrum was the strongest at 1085.3 nm(1.1424 eV) of photoluminescence spectrum at 10 K, and also FWHM of Double Crystal X-ray Rocking Curve (DCRC) was the smallest, 129 arcsec. The Hall effect on this sample was measured by the method of Van der Pauw, and the carrier density and mobility dependent on temperature were 9.57x10/sup 22/ electron/㎥, 1.31x10/sup -2/㎡/V·s at 293 K, respectively. The ΔCr(Crystal field splitting) and the ΔSo (spin orbit coupling splitting( measured at f10K from the photocurrent peaks in the short wavelength of the CuInTe₂ single crystal thin film were about 0.1200 eV, 0.2833 eV respectively. From the PL spectra of CuInTe₂ single crystal thin film at 10 K, the free exciton (E/sub x/) was determined to be 1064.5 nm(1.1647 eV) and the donor-bound exciton(D/sup 0/, X) and acceptor-bound exciton (A/sup 0/, X) were determined to be 1085.3 nm(1.1424 eV) and 1096.8 nm(1.1304 eV0 respectively. And also, the donor-acciptor pair (DAP)P/sub 0/, DAP-replica P₁, DAP-replica P₂ and self-activated (SA) were determined to be 1131 nm (1.0962 eV), 1164 nm(1.0651 eV), 1191.1 nm(1.0340 eV) and 1618.1 nm (0.7662 eV), respectively.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.140-148
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• 2022

This study focuses on the finding out the structural effect of consumers' cognitive age affecting consumer innovativeness due to the mediating effect of perceived easy of use of mobile and perceived usefulness of mobile. For this study, a self report survey is conducted through a structured questionnaire, and a parallel double-mediated effect analysis is performed using the process macro of SPSS for the analysis. In the study results, it is found that the cognitive age of consumers directly have a statistically significant negative effect on consumer innovativeness. In addition, in the analysis to verify the mediating effect of perceived easy of use of mobile and perceived usefulness of mobile, it is shown that perceived usefulness of mobile has a positive and significant effect on consumer innovativeness. Through this, The contribution of this study can be attributed to the fact that it analyzed the structural relationship between the perceived ease of use of mobile and the perceived usefulness of mobile in the process of consumers' cognitive age affecting consumer innovativeness.

• Molecules and Cells
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• v.43 no.5
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• pp.448-458
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• 2020

T-DNA insertional mutations in Arabidopsis genes have conferred huge benefits to the research community, greatly facilitating gene function analyses. However, the insertion process can cause chromosomal rearrangements. Here, we show an example of a likely rearrangement following T-DNA insertion in the Anti-Silencing Function 1B (ASF1B) gene locus on Arabidopsis chromosome 5, so that the phenotype was not relevant to the gene of interest, ASF1B. ASF1 is a histone H3/H4 chaperone involved in chromatin remodeling in the sporophyte and during reproduction. Plants that were homozygous for mutant alleles asf1a or asf1b were developmentally normal. However, following self-fertilization of double heterozygotes (ASF1A/asf1a ASF1B/asf1b, hereafter AaBb), defects were visible in both male and female gametes. Half of the AaBb and aaBb ovules displayed arrested embryo sacs with functional megaspore identity. Similarly, half of the AaBb and aaBb pollen grains showed centromere defects, resulting in pollen abortion at the bi-cellular stage of the male gametophyte. However, inheritance of the mutant allele in a given gamete did not solely determine the abortion phenotype. Introducing functional ASF1B failed to rescue the AaBb- and aaBb-mediated abortion, suggesting that heterozygosity in the ASF1B gene causes gametophytic defects, rather than the loss of ASF1. The presence of reproductive defects in heterozygous mutants but not in homozygotes, and the characteristic all-or-nothing pollen viability within tetrads, were both indicative of commonly-observed T-DNA-mediated translocation activity for this allele. Our observations reinforce the importance of complementation tests in assigning gene function using reverse genetics.

• The Journal of Korean Physical Therapy
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• v.22 no.2
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• pp.15-23
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• 2010

Purpose: This study was done to establish reference data for temporo-spatial, kinematic and kinetic parameters for normal Koreans as they age. Methods: Normal adults and children without a previous history of musculoskeletal problems were enrolled in this study. The normal subjects were divided by age into three groups: Group I: children ($11.95{\pm}0.29$ years); Group II: young adults ($23.90{\pm}3.67$ years); Group III: older adults ($71.40{\pm}4.08$ years). The temporo-spatial and kinematic data were measured using 6 MX3 cameras while each subject walked through a 10 m walkway at a self-selected speed. The kinetic data were measured using 2 force plates and were calculated by inverse dynamics. Results: Motion patterns are typically associated with a specific phase of the gait cycle. Our results were as follows: 1. There were significant differences between the different age groups in temporo-spatial parameters such as cadence, double support, time of foot off, stride length, step length, and walking speed. 2. There were significant differences between the groups in kinematic parameters such as range of motion (ROM) of the hip, knee and ankle in the sagittal plane, ROM of the pelvis, hip and knee in the coronal plane and ROM of the pelvis, hip and ankle in the transverse plane. 3. There were significant differences between the groups in kinetic parameters such as joint moments of force, joint mechanical power generation or absorption and ground reaction forces. Conclusion: The results of this study can be utilized (a) as a reference for kinematic and kinetic data of gait analysis in normal Koreans, and (b) as an aide in evaluating and treating patients who have problems relating to gait.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8C
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• pp.827-834
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• 2003

In this paper, we implemented an optical information security system using computer generated hologram based on the principle of interference and BaTiO$_3$that is photorefractive material. First of all, we would generate binary phase hologram which can reconstruct the original image perfectly, and regard this hologram as the image to be encrypted. And then applying the interference rule to the hologram, encrypted and reference (fkey information) images are generated. In the decrypting process, we can get an interference intensity by interfering the reference image and the encrypted image in the Mach-Zehnder interferometer. and transforming interference intensity information into phase information using LCD(liquid crystal display) and finally recover original image by inverse Fourier transforming the phase information. In this process, the Intensity information generated by interference of two images is very sensitive to external vibrations. So, we get a stable interference using the characteristic of SPPCM(self pumped phase conjugate mirror) of BaTiO$_3$that is photorefractive material. The proposed method has an advantage of double image encryption by encrypting the hologram of the image instead of original image.