• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.4
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• pp.29-43
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• 2000

This study is carried out to investigate the cahracteristics of green management practices and green speed(i.e., ball-roll distance) on 129 Golf Courses in Korea, and to explain the effects of managemet practices that affect green speed. Data collected from green-keepers were subjected to frequency, correlation analysis, and multi-regression analysis using SPSSWIN(Statistical Package for the Social Science). The results are as follows. 1. In spring mowing height, 3.5-4 mm appeared the highest frequency(44.4%) and 4-4.5mm mowing height appeared the high frequency(41.0%). In summer mowing height, 4.5-5mm appeared the highest frequency(51.3%). In fall mowing height, 4-4.5mm appeared the highest frequency(41.0%). 2. In N-fertilizing amount of February and November, 0(zero) g/$m^2$ appeared the highest frequency. In N-fertilizing amount, of June and July 0-2 g/$m^2$ appeared the highest frequency. In N-fertilizing amount, of March, May, August, and September 2-4 g/$m^2$ appeared the highest frequency. In N-fertilizing amount, of October 2-4 or 6-8 g/$m^2$ appeared the highest frequency. 3. In spring topdressing times, 3-6 times appeared the highest frequency(52.6%). In spring topdressing amount, more than 2mm appeared the highest frequency(35.9%). In summer topdressing tierms, 0-3times appeared the highest frequency(71.8%). In summer topdressing amount, 0.5-1mm appeared the highest frequency(46.2%). In fall topdressing times, 0-3times appeared the highest frequency(47.4%). In fall topdressing amount, more than 2mm appeared the highest frequency(35.9%). 4. In spring irrigation tiems, 3-4times/a week appeared the highest frequency (30.6%). In spring irrigation amount, the irrigation below 5mm/day under appeared the highest frequency(38.7%). In summer irrigation times, 4-7times/ a week appeared the highest frequency(38.9%). In summer irrigation amount, 5-10mm/a day appeared the highest frequency(45.2%). In fall irrigation times, 2-3times/a week appeared the highest frequency(36.1%). In fall irrigation amount, the irrigation below 5mm/a day under appeared the highest frequency(45.2%). 5. In spring aeration times, 2 times appeared the highest frequency(55.2%). In spring aeration depth, 5-10mm appeared the highest frequency(81.6%). In fall aeration times, 1 time appeared the highest frequency(82.5%). In fall aeration depth, 5-10mm appeared the highest frequency(86.8%). 6. In spring green speed, 1.98-2.28 or 2.59-2.89mm appeared the highest frequency(32.7%). In summer green speed, 1.98-2.28mm appeared the highest frequency (46.9%). In fall green speed, 1.98-2.28mm appeared the highest frequency(38.8%). 7. The factors which affect green speed were mowing height, N-fertilizing, season, topdressing, irrigation, and aeration. Vertical mowing did not affect green speed. The order of the relevant important factors was mowing height >: N-fertilizing > season > topdressing > irrigation > aeration. Mowing height and N-fertilizing were the most important factors in green speed. As mowing height decreased, green sped always increased. As total N-fertilizing amount decreased, green speed increased. In summer, green sped decreased remarkably. As topdressing times increased and the topdressing amount decreased, green sped increased. As irrigation times increased and irrigation amount decreased, green speed increased.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.1
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• pp.1-8
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• 2012

This study was carried out in 2010 to investigate the utilization and forage quality of native grasses, such as $Phragmites$ $communis$ which might reduce the cost of feeding domestic cattle. The regions surveyed were the Haenam ranch in Haenam, Pyeongchang, Wonju, and Yeonggwang. In Haenam, yearly silage production harvested from 300 ha was 2,000 MT (7 MT/ha). All of those round bale silages were self-consumed in that region, and marketing price was 50,000~55,000 won per roll (110 won/kg). $Phragmites$ $communis$ of 150 cm in length contained 8.4% crude protein (CP) with relative feed value (RFV) 71.9 and 60.1% in vitro dry matter digestibility (IVDMD), which was somewhat more favorable than forage quality of rice straw. The silage quality of $Phragmites$ $communis$ varied greatly by the time of harvest (CP 4.7~6.4%, RFV 62.2~78.9, and IVDMD 41.9~53.9%), even with the same district and of the same original forage materials. Generally, the quality of $Phragmites$ $communis$ silage of was poorer than that of sorghum ${\times}$ sudangrass hybrid. In Pyeongchang, forage quality of $Phragmites$ $communis$ was decreased from 13.9% to 7.6% in CP, 90.7 to 76.1 in RFV, and 72.9% to 54.7% in IVDMD, as plant was getting mature, from 79 cm to 117 cm, 121 cm or to 142 cm in length. In Wonju, the quality values of $Phragmites$ $communis$ of 130 cm in length were 8.5% CP, 82.3 RFV and 70.2% IVDMD, while those of matured grasses of 220 cm in length were lower (10.2% CP, 65.1 RFV and 48.9% IVDMD), but this was a little more favorable than quality of rice straw. In Yeonggwang, feeding $Phragmites$ $communis$ was tried in a Hanwoo feed, but stopped due to low profitability. In conclusion, the overall quality of most native grasses including $Phragmites$ $communis$ in this survey was poor. Therefore, we recommend that $Phragmites$ $communis$ and native grasses should be harvested on June or July to obtain richer forage quality in forage values than rice straw.

• Journal of Korean Society of Disaster and Security
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• v.13 no.1
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• pp.59-75
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• 2020

This study is a case study that applied 'UNDRR's Urban Disaster Resilience Scorecard', an evaluation tool necessary for Incheon Metropolitan City to be certified as an international safe city. I would like to present an example that the results derived from this scorecard contributed to the Incheon Metropolitan City Disaster Reduction Plan. Of course, the Disaster Resilience Scorecard can't provide a way to improve the resilience of every disaster facing the city. However, it is to find the weakness of the resilience that the city faces, and to propose a solution to reduce the city's disaster risk. This is to help practitioners to recognize the disaster risks that Incheon Metropolitan City faces. In addition, the solution recommended by UNDRR was suggested to provide resilience in areas vulnerable to disasters. It was confirmed that this process can contribute to improving the disaster resilience of Incheon Metropolitan City. UNDRR has been spreading 'Climate Change, Disaster-resistant City Creation Campaign', aka MCR (Making Cities Resilient) Campaign, to cities all over the world since 2010 to reduce global cities' disasters. By applying the disaster relief guidelines adopted by UNDRR, governments, local governments, and neighboring cities are encouraged to collaborate. As a result of this study, Incheon Metropolitan city's UN Urban Resilience Scorecard was evaluated as a strong resilience field by obtaining scores of 4 or more (4.3~5.0) in 5 of 10 essentials; 1. Prepare organization for disaster resilience and prepare for implementation, 4. Strong resilience Urban development and design pursuit, 5. Preservation of natural cushions to enhance the protection provided by natural ecosystems, 9. Ensure effective disaster preparedness and response, 10. Rapid restoration and better reconstruction. On the other hand, in the other five fields, scores of less than 4 (3.20~3.85) were obtained and evaluated as weak resilience field; 2. Analyze, understand and utilize current and future risk scenarios, 3. Strengthen financial capacity for resilience, 6. Strengthen institutional capacity for resilience, 7. Understanding and strengthening social competence for resilience, 8. Strengthen resilience of infrastructure. In addition, through this study, the risk factors faced by Incheon Metropolitan City could be identified by priority, resilience improvement measures to minimize disaster risks, urban safety-based urban development plans, available disaster reduction resources, and integrated disasters. Measures were prepared.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2005.09a
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• pp.201-212
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• 2005

[ $Epoxy/BaTiO_3$ ] composite embedded capacitor films (ECFs) were newly designed fur high dielectric constant and low tolerance (less than ${\pm}15\%$) embedded capacitor fabrication for organic substrates. In terms of material formulation, ECFs are composed of specially formulated epoxy resin and latent curing agent, and in terms of coating process, a comma roll coating method is used for uniform film thickness in large area. Dielectric constant of $BaTiO_3\;&\;SrTiO_3$ composite ECF is measured with MIM capacitor at 100 kHz using LCR meter. Dielectric constant of $BaTiO_3$ ECF is bigger than that of $SrTiO_3$ ECF, and it is due to difference of permittivity of $BaTiO_3\;and\;SrTiO_3$ particles. Dielectric constant of $BaTiO_3\;&\;SrTiO_3$ ECF in high frequency range $(0.5\~10GHz)$ is measured using cavity resonance method. In order to estimate dielectric constant, the reflection coefficient is measured with a network analyzer. Dielectric constant is calculated by observing the frequencies of the resonant cavity modes. About both powders, calculated dielectric constants in this frequency range are about 3/4 of the dielectric constants at 1 MHz. This difference is due to the decrease of the dielectric constant of epoxy matrix. For $BaTiO_3$ ECF, there is the dielectric relaxation at $5\~9GHz$. It is due to changing of polarization mode of $BaTiO_3$ powder. In the case of $SrTiO_3$ ECF, there is no relaxation up to 10GHz. Alternative material for embedded capacitor fabrication is $epoxy/BaTiO_3$ composite embedded capacitor paste (ECP). It uses similar materials formulation like ECF and a screen printing method for film coating. The screen printing method has the advantage of forming capacitor partially in desired part. But the screen printing makes surface irregularity during mask peel-off, Surface flatness is significantly improved by adding some additives and by applying pressure during curing. As a result, dielectric layer with improved thickness uniformity is successfully demonstrated. Using $epoxy/BaTiO_3$ composite ECP, dielectric constant of 63 and specific capacitance of 5.1nF/cm2 were achieved.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.200-208
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• 2017

Despite a rapid market growth in VR, cyber sickness has become the most serious problem in terms of user experience. The aim of this study is to verify whether there are differences in user's perception of cyber sickness by the point-of-view and the movement in VR contents. An experimental testing of game playing with VR headset was conducted on the effects of two conditions: first-person and third-person views in the point-of-view condition, and yaw - pitch rotations in the head movement condition. The results showed that cyber sickness worsened in the first-person point-of-view and in the yaw rotation movement. Point-of-view and movement had main effects on the cyber sickness, but an interaction effect between point-of-view and movement was not found. Based on the findings, along with reducing VR sickness, we proposed practical implications for VR contents planning for building balanced VR user experience. Positive VR experience can be reinforced through visual design, multi-modal interface design, and experience marketing for the optimal level of contents immersion. A future research was suggested on the roll rotation for diverse content genre development.

• Journal of Biomedical Engineering Research
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• v.34 no.3
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• pp.129-134
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• 2013

The essential tremor is an involuntary oscillatory movement of body parts. Conventional treatments of essential tremor have little effects in some patients and also leads to significant side effects. Alternative to these treatments, sensory stimulation may have beneficial effects on the essential tremor. The purpose of this study was to analyze an effect of sensory stimulation on essential tremor. Ten patients with essential tremor ($67.4{\pm}8.82$ yrs, 5 men and 5 women) participated in this study. Three-axis gyro sensors were attached on index finger, hand and forearm of patients. Task of 'arms outstretched forward' was performed with and without sensory stimulation. Vectorsum of three dimensional angular velocities (pitch, roll, yaw) was calculated. Outcome measures included root-meansquare (RMS) mean of the vector-sum amplitude, total power, peak power and peak frequency. RMS amplitude, total power and peak power were reduced by sensory stimulation (p < 0.05). Peak frequency was not affected by sensory stimulation. The results indicate that the sensory stimulation is useful to suppress the essential tremor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.653-659
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• 2018

High-rise buildings and complex facilities are a representative urban system for the masses, and it requires an increasing role of commodity and safety. Smoke and toxic gasses can cause accidents due to fire in these systems. The purpose of this study is to develop a fiber screen material for emergency evacuation passages that can be avoided quickly and safely in cases of disasters. The fiber screen material is applicable to folding devices for emergency evacuation passages. The material is different from general steel material in that it is lightweight with less burden during storage for a long time in a roll form in a folding device. It also has an excellent secondary function in that it is less affected by radiant heat. Three kinds of fiber screen materials were selected that have good flame retardancy and post-processing characteristics. A performance evaluation was performed by a heat shrinkage test, contact heat test, combustibility test, flame retardancy test, tensile strength test, and tear strength test. As a result, the lightweight fabric shows excellent performance through post-processing, and silicone resin coating can secure safety of the pizza by the fiber screen material performance and radiant heat. The optimum post-treatment conditions were evaluated by performing a burning test after coating two kinds of glass fibers and four types of flame-retardant silicone resins with different weight and thickness.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.276-276
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• 2017

This study was examined to establish a conditions for producing Tteokbokki using dry-milling rice flour which can save manpower and labor time. Since the cost of producing rice flour milled in a wet condition is 500 to 700 won/kg, which is more than twice as much as that of 300 won wheat flour, it is necessary to directly make rice flour from raw rice. The dry-milling rice flour used in the experiment was produced by Air mill (Nara machinary co. ltd., Tokyo, Japan) from 5 rice cultivars (Samkwang, Dasan-1, Boramchan, Seolgaeng, Hanareum-2), which were cultivated in A-san in 2015 year. Their particle sizes were 50, 100 and $150{\mu}m$ for each cultivar, respectively. A control was a wet-milled rice flour milled with a roll mill after the rice was soaked in water for 4 hours. The moisture content of dry-milling rice flour based on cultivars was 11 ~ 12%, and added water up to 50~55% of dry-milling rice flour weight. The RVA characteristic of peak viscosity was the highest in Dasan-1 and Hanareum-2, the lowest in Seolgaeng. The setback value used as an indicator of aging was the highest in Dasan-1, therefore Dasan-1 was expected to be quick solidification, resulting in the low tendency of sensory evaluation. The damaged starch was high in Dasan-1 and Boramchan (p<0.05) compared to others. The Hunter color L were no significant among cultivars and b value increased in all cultivars of dry-milling rice flour compared with control. The hardness of dry-milling rice flour was higher than that of the control, especially Dasan-1 and Hanareum-2 were the highest. Based on the sensory evaluation, the best cultivars were Boramchan, Hanareum-2 and Samkwang. The overall preference of dry-milling rice flour was good in particle size of 50~100um.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1119-1122
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• 2006

Aeration by using diffusers usually requires approximately 50~90% of the total electricity needed to operate WWTP (WasteWater Treatment Plant)s. Accurate evaluation of the oxygen transfer efficiency for an aeration system, and recommendation of a better alternative may help saving WWTP operational costs. Appropriate techniques and methods to achieve this purpose have not been introduced in Korea. In this study, in-process analysis was performed for a coarse bubble aeration system by the off-gas method to evaluate its applicability in Korea. To accomplish this analysis, an off-gas test, unsteady-state clean water test and steady-state off-gas column test was conducted and comparisons to other aeration systems were made. The ${\alpha}$ and the F estimated from the results of the unsteady-state clean water test and the steady-state off-gas column test were 0.61 and 0.90 respectively in a coarse bubble aeration system. The comparison of P.E tube diffusers laid out single spiral roll and ceramic dome diffusers laid out full floor coverage showed that the oxygen transfer efficiency of the coarse bubble aeration system was less than or similar to other aeration systems. But, airflow rates per unit area were 4~5 times greater than other aeration systems. In regards to the oxygen transfer efficiency for airflow rates per unit area, a retrofit to higher efficiency diffusers was urgently needed. This study showed proved that off-gas methods can apply to evaluate diffuser performances to estimate operating factors and to compare other aeration systems in Korea.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.67-88
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• 1992

The purpose of this study was to investigate the changes of mandibular movement and muscle activity following orthognathic surgery in patients with mandibular prognathism. Lateral cephalogram, M.K.G., E.M.G. recordings were obtained immediately before surgery, and 2 months and 8 months after surgery. Among the patients who received orthognathic surgery, 19(13 men, 6 women) were selected for this study. Statistical analysis for each time interval differences were performed with the SPSS package. The results were as follows: 1. Compared with the pre-operative group (opening 349.7mm/sec, closing 313.1mm/sec), the mean values of the maximum opening and closing velocity in the skeletal Class III surgery group were significantly decreased in the 2 months post-operative (opening 232.9mm/sec, closing 206.9mm/sec), but the values tended to increase in the 8 months post-operative group (opening 280.9 mm/sec, closing 319.1mm/sec). 2. Compared with the pre-operative group (61.7 mm/sec), the maximum velocity of the terminal tooth contact increased in the 2 months (72mm/sec) and 8 months (105.7mm/sec) postoperative groups. 3. In the mean value of vertical freeway space, there was significant difference between the normal group and the pre-operative group, but not between the normal group and the 8 months post-operative group. 4. In the mean values of the maximum opening, the maximum anterio-posterior movement from centric-occlusion, and the lateral deviation from centric occlusion, there was no significant difference between the normal group and the surgery group (the pre-operative and the 8 months post-operative groups). 5. The mature swallowing pattern was 58% in the pre-operative group, but 90% in the 2 months post-operative group, and 63% in the 8 months post-operative group. 6. In the comparison of muscle activity, there was no significant difference between the normal group and the surgery group during the rest position. However, during cotton roll clenching, there was significant difference between the normal group and the pre-operative group, but not between the normal group and the 8 months post-operative group.