• Geomechanics and Engineering
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• v.19 no.2
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• pp.193-199
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• 2019

A frozen fringe plays a key role in frost heave development in soils. Previous studies have focused on the physical and mechanical properties of the frozen fringe, such as overall hydraulic conductivity, water content and pore pressure. It has been proposed that the thickness of the frozen fringe controls frost heave behavior, but this effect has not been thoroughly evaluated. This study used a temperature-controllable cell to investigate the impact of frozen fringe thickness on the characteristics of frost heave. A series of laboratory tests was performed with various temperature boundary conditions and specimen heights, revealing that: (1) the amount and rate of development of frost heave are dependent on the frozen fringe thickness; (2) the thicker the frozen fringe, the thinner the resulting ice lens; and (3) care must be taken when using the frost heave ratio to characterize frost heave and evaluate frost susceptibility because the frost heave ratio is not a normalized factor but a specimen height-dependent factor.

• Journal of Audiology & Otology
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• v.23 no.1
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• pp.49-52
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• 2019

Background and Objectives: Considering important role of vitamin D in many physiological processes including vestibular system in the ear, aim of present study is to evaluate saccule function via cervical vestibular evoked myogenic potential (cVEMP), in patients with vitamin D deficiency. Subjects and Methods: After routine audiological tests, cVEMP were recorded in 15 patients with vitamin D deficiency and 16 normal subjects. The short tone burst (95 dB nHL, 500 Hz) was presented to ears. cVEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid muscle. Results: Mean of p13, n13, interpeak latencies and amplitude ratios were measured in both groups. Statistical analysis did not show differences between two groups. Conclusions: Maybe serum 25-hydroxyvitamin D concentration was not low enough to have effect on saccule in the patients in present study or saccule have had low susceptibility to effects of vitamin D deficiency. For better judgment about effect of vitamin D deficiency on saccular function planning studies with high sample size is recommended.

• Korean Journal of Audiology
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• v.23 no.1
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• pp.49-52
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• 2019

Background and Objectives: Considering important role of vitamin D in many physiological processes including vestibular system in the ear, aim of present study is to evaluate saccule function via cervical vestibular evoked myogenic potential (cVEMP), in patients with vitamin D deficiency. Subjects and Methods: After routine audiological tests, cVEMP were recorded in 15 patients with vitamin D deficiency and 16 normal subjects. The short tone burst (95 dB nHL, 500 Hz) was presented to ears. cVEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid muscle. Results: Mean of p13, n13, interpeak latencies and amplitude ratios were measured in both groups. Statistical analysis did not show differences between two groups. Conclusions: Maybe serum 25-hydroxyvitamin D concentration was not low enough to have effect on saccule in the patients in present study or saccule have had low susceptibility to effects of vitamin D deficiency. For better judgment about effect of vitamin D deficiency on saccular function planning studies with high sample size is recommended.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.3
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• pp.254-263
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• 2012

The survivability of warship is assessed by susceptibility, vulnerability and recoverability. Essentially, a vulnerability assessment is a measure of the effectiveness of a warship to resist hostile weapon effects. Considering the shot line and its penetration effect on the warship, present study introduces the procedural aspects of vulnerability assessments of warship. Present study also considers the prediction of penetration damage to a target caused by the impact of projectiles. It reflects the interaction between the weapon and the target from a perspective of vulnerable area method and COVART model. The shotline and tracing calculation have been directly integrated into the vulnerability assessment method based on the penetration equation empirically obtained. A simplified geometric description of the desired target and specification of a threat type is incorporated with the penetration effect. This study describes how to expand the vulnerable area assessment method to the penetration effect. Finally, an example shows that the proposed method can provide the vulnerability parameters of the warship or its component under threat being hit through tracing the shotline path thereby enabling the vulnerability calculation. In addition, the proposed procedure enabling the calculation of the component's multi-hit vulnerability introduces a propulsion system in dealing with redundant Non-overlapping components.

• YAKHAK HOEJI
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• v.55 no.3
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• pp.227-233
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• 2011

We previously reported the protein isolated from Coptidis Rhizoma (CRP), which has antifungal activity against a fungal pathogen, Candida albicans. In the current study, we investigated what portion in the CRP is responsible for the antifungal activity. For the investigation, the CRP was fractionated on a Shepadex G-50 column. Data resulting from the fractionation, seven fractions were obtained. Fractions (Fr.) I, II, and III eluted initially from the column showed no inhibitory effect on the growth of C. albicans, whereas Fr. IV, V, and VI eluted later revealed inhibition of the growth, and Fr. IV and VI showed potent antifungal activity by broth susceptibility analysis. However, Fr. VI was contained in the CRP more than Fr. IV, which led us to select the VI for the following experiments. In a murine model of a subcutaneous candidiasis caused by C. albicans, the Fr. VI displayed a therapeutic effect on nude mice pretreated with anti-neutrophil monoclonal antibody (RB68C5) and then infected subcutaneously with live C. albicans. At day 16, these mice were healed almost up to 78% of the infected area when compared to infected area of control nude mice that received diluent (Dulbecco's Phosphate-Buffered Saline; DPBS), instead of the Fr. VI (P<0.01). The Fr. VI blocked hyphal formation from blastoconidial form of C. albicans (P<0.01), which might prevent penetration of hyphae to the deeper site of skin and thus helps the healing. In the ionic strength test, the effect of Fr. was influenced by $Ca^{2+}$ ion just like other known antimicrobial peptides, but the influence was affected at an extremely high concentration such as 500 mM. Thus, such ion-concentration is considered to be meaningless in the clinical situation. Considering all data together, Coptidis Rhizoma is appeared to produce an antimicrobial peptide that has therapeutic effect on subcutaneous infection caused by C. albicans.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.75-81
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• 2000

These studies were carried out to investigate the toxicities of 38 registered insecticides to the sweetpotato whitefly (Trialeurodes vaporariorum). Insecticide activities were evaluated by testing systemic action and residual effect in the laboratory, and control efficacy in the greenhouse. All experiments were tested at the recommended concentration(ppm) of each insecticides. Insect growth regulators (IGRs), only pyriproxyfen showed over 90% of ovicidal effect. The insecticides that showed over 90% of larvicidal activity oil 3rd nymphal instars were abamectin, acetamiprid, chlorpyrifos-methyl, imidacloprid, pyripoxyfen, and acetamiprid+ethofenprox. Insecticides with 100% adulticidal activity were abamectin, acephate, acetamiprid, benfurcarb, bifenthrin, furathiocarb, endosulfan, fenitrothion, imidacloprid, phenthoate, pymetrozine, acetamiprid + ethofenprox, ethofenprox + diazinon, furathiocarb + difluberlzuron, and triazamate+${\alpha}$-cypermethrin. Abamectin, acetamiprid, imidacloprid, pyriproxyfen, and acetamiprid + ethofenpox showed both residual effect and systemic activity. In tile control efficacy test on B. tabaci, 90% control values were obtained at 11th day after treatment of the insecticides including abamectin, acetamiprid, imidacloprid, pyripoxyfen and acetamiprid + ethofenprox. These results indicate that abamectin, acetamiprid, imidacloprid, pyriproxyfen and acetamiprid + ethofenprox can be used for tile control of B. tabaci in field.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.345-355
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• 2021

This study examined the factors that influence the use of YouTube-based home training contents by integrating and applying the technology acceptance model and health belief model. The main results are as follows. First of all, it was found that personal innovativeness had a positive (+) effect on perceived ease and perceived usefulness. Perceived susceptibility did not have a significant effect on perceived usefulness, and perceived benefit had a positive (+) effect on perceived usefulness. Finally, it was found that perceived ease had a positive (+) effect on perceived usefulness, Both perceived ease of use and perceived usefulness were found to have a positive (+) effect on continuous intention to use. This study will be meaningful in that it partially reconfirmed the possibility of integrating the technology acceptance model and the health belief model.

• Research in Plant Disease
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• v.14 no.3
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• pp.143-152
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• 2008

Mixed-planting of two rice cultivars, HP ('Hopyeongbyeo') and NP ('Nampyeongbyeo'), having a dissimilar susceptibility to rice blast was practiced for chemical-free control of rice blast in the field. The HP/NP combination was selected for applying under mechanized agricultural conditions. Because they have similar genetic characteristics such as seed germination and heading time, culm length, rice quality and size of rice grains except susceptibility to blast. Incidence of panicle blast was reduced 50.4 % compare with supposed blast incidence by HP/NP mixed-planting when the seeds of two cultivars were combined 1 to 1 as weight. Supposed blast incidence was estimated from reduction of rice blast caused by addition of a resistant cultivar NP. Race diversity of Magnaporthe oryzae was examined for correlation with control effect of HP/NP mixed-planting on rice blast. The population of dominant race KJ-101 was diminished and replaced with various co-existing races and eleven new races were appeared in mixed-planting plot. Total number of race isolated from mixed-planting plot was not largely different from mono-culture. However, detection frequency of the new race was increased and variation of the population size of each race was decreased in mixed-planting plots. It was shown that a biased community with a dominant race (KJ-101 or KI-181) was altered to a balanced one of coexisting races. From these results, it was supposed that the balanced diversity among co-existing races within a community might be correlated to control effect by HP/NP mixed-planting on rice blast. Further more, it should be studied that genetic characteristics of the individual race including a virulence on cv. HP and NP was examined for verifying a correlation of mixed-planting effect and race diversity.

• Korean journal of applied entomology
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• v.50 no.1
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• pp.39-46
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• 2011

This study analyzed effects of different sound treatments in frequencies and intensities on digestion and immune physiological processes of the beet armyworm, Spodoptera exigua larvae. Without effect on egg hatch, sound treatments with 100-5,000 Hz at 95 dB suppressed feeding behavior and inhibited a digestive enzyme activity. In addition, two dimensional electrophoresis of midgut luminal proteins indicated a marked difference of the sound-treated larvae. In response to 5,000 Hz at 95 dB, larvae showed a significant decrease in hemocyte nodule formation against fungal challenge along with significant suppression in phospholipase $A_2$ activity in hemocyte and plasma. With increase of sound frequencies, the treated larvae showed an enhanced susceptibility to insecticides. Such sound frequency effect was significantly modulated with different sound intensities. These results suggest that sound treatment may give adverse stress to physiological processes of S. exigua larvae and may be applied to a nonchemical insect pest control.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.703-709
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• 1993

The changes in molecular size distribution of rice starch during extrusion cooking and simple heating of rice flour were compared and the effect of subsequent enzyme treatment on the molecular size was examined. A single-screw extruder was used with varing feed moisture contents ($17{\sim}29%$) and barrel temperatures ($100{\sim}150^{\circ}C$). An aluminium capsule immersed in oil bath ($100{\sim}200^{\circ}C$) was used for the simple heat treatment of rice flour. In case of extrusion cooking the mechanical energy input varied sharply at around 23% moisture content of the feed. At the feed moisture content of $17{\sim}23%$, a significant molecular size reduction of rice starch was observed by the gel permeation chromatography using Sephacryl S-1000 gel. The intact starch molecules of above $4{\times}10^{7}$ dalton were largely disintergrated by extrusion cooking of rice flour containing the moisture content less than 23%. It was mostly degraded further into the molecules having below $5{\times}10^{6}$ dalton by ${\alpha}-amylase$ treatment. But at the feed moisture content above 26% the starch did not show molecular size reduction either by extrusion cooking or by subsequent enzyme treatment. On the contrary little changes in molecular size of starch was occured by simple heating of rice flour containing the moisture less than 20%. but slight size reduction was observed at the moisture content above 23%, where the effect of ${\alpha}-amylase$ was also observed.