• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.52-59
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• 2014

The aims of this paper are to characterize the transient overvoltages(TOVs) and to evaluate the risk occurring at 22.9kV consumer's substation. The measurements of lightning- and switching-caused TOVs were made during Mar. 2013 and Feb. 2014. As a consequence, 47 events of TOVs were recorded and 4 of them were higher than the input voltage envelope(IVE) of the information technology industry council(ITI) curve. The measured TOVs are characterized by longer front times and longer durations compared to the $1.2/50{\mu}s$ standard impulse voltage waveform, and some of them represent bipolar waves with lower oscillation frequencies. It suggests that the test of non-standard impulse voltage waveforms is needed for effective risk assessments of power apparatus. Lightning- and switching-caused TOVs exceeding IVE of ITI curve are induced at the secondary of 22.9kV potential transformer(PT). We may, therefore, conclude that the surge protection devices should be applied at the secondary of PT and the surge absorbers should be installed at the primary of VCB or PT. The results presented in this paper could be useful to design the reasonable insulation coordination for 22.9kV consumer's substation.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.5
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• pp.11-19
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• 2003

The main purpose of this study was to examine the application of the root system as a shore protection material through the measurement of the 개ot growth curve of Salix gracilisyla Miq. depending on the cutting size. As materials and methodology, nine group of cuttings were classified by the length(l0cm, 20cm, 40cm) and the diameter(0.72cmm$\pm$0,02, 0.58cm$\pm$0.02, 0.35cm$\pm$0.02), Each group was stuck to a flooding bed of sandy loam(Sand 60,36%, Silt 28%, Clay 11.64%) on 27th March 2001, After 65 growing days, the weight and length of the newly developed roots, shoots, and leaves were measured and analysed, This was repeated at 99, 129, 159, and 190 growing days. The major findings were as follows. The primary determinant of the root growth rate was on the weight of cutting, The secondary determinant was on the number of growing days. In addition, the dominant dimension of the cutting was the diameter rather than the length, The thicker cutting caused more rapid and stable growth however the longer cutting made the growth of the root slower and more unstable.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.6
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• pp.834-844
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• 2000

In this study, an off-design performance analysis procedure is developed based on Two-zone model and TEIS model. In Two-zone model, there are both primary zone and secondary zone for an isentropic core flow and an average of all non-isentropic streamtubes respectively. The level of the core flow diffusion in an impeller is calculated by using TEIS model which regards the impeller as two successive rotating elements in series. At impeller exit, the mixing process occurs with an increase in entropy, that is to say, a decrease in total pressure. In loss models including Two-zone and TEIS model, some empirical parameters have a great influence on overall performance curve. So these parameters' influences on the overall performance curve are investigated and compared with experimental data.

• Water for future
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• v.24 no.1
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• pp.63-71
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• 1991

This study represents the methodology for feasibility analysis of small hydro power plants. Cumulative density function of Weibull distribution and Thi-essen method were adopted to beside flow duration curve at candidate sites. The performance prediction model and construction cost estimation model for tunnel-type small hydro power plants were developed. Eight candidate sites existing on Han river selected and surveyed for actual sites reconnaissance. The performance characteristics and economical feasibility for these sites were analyzed by using developed models. As a result, it was found that the optimum design flowrates with the lowest unit generation cost for tunnel-type small hydro power plants were the flowrate concerning with between 20 % and 30 % of time ratio on the flow duration curve. Additionally, primary design specifications such as design flowrate, effective head, capacity, annual average load factor, annual electricity production were estimated and discussed for surveyed sites.

• Journal of Fashion Business
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• v.7 no.6
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• pp.1-9
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• 2003

This study has as its primary aims the following: to create a fashion design based on the aesthetic value of Art Nouveau which flourished from the end of 19 century to the beginning of 20 century. In this thesis, two themes, Rose Aroma and Iris Memory are selected among the flower patterns and are used to create two works. First, the Rose Aroma theme is for an evening dress of S-curve style made with Silk Jacquard based on rose image of Art Nouveau. For decoration, artificial rose and its stem, and leaves are used to highlight hip line. By such design associated with a flower garden, cubic effects are expressed as a design point. Second, the Iris Memory theme is for a wedding dress made with tulle based on Iris image of Art Nouveau. This dress has a special point in its top bra, underwear used like an outer garment, involving spangle, beads, pearl, and cubic in order to enhance its visual effect. These works are significant in presenting the development possibilities of various fashion designs by introducing Art Nouveau style into diverse modern fashions.

• Textile Coloration and Finishing
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• v.24 no.4
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• pp.296-304
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• 2012

For development of dyeability, the cotton fabric was dyed repeatedly with persimmon juice by padding mangle. We evaluated the mechanical properties and hand value by Kawabata Evaluation System, and observed the change of surface morphology. The results obtained from this study were as follows. With the increase of repeating padding times of dyeing, the linearity of load-extension curve and tensile energy per unit length of the cotton fabric were increased, but the tensile resilience of fabric was decreased. The value of shear stiffness and shear hysteresis were increased. Also compression resilience and linearity of compression thickness curve were increased. The cotton fabric dyed with persimmon juice had shown the thickness and weight increase as the number of padding increase. As repeating times of dyeing with persimmon juice were increased, among the 6 hand values, the item of stiffness, anti-drape stiffness, fullness and softness were increased, while flexibility with soft feeling and crispness were greatly decreased. The amount of coated persimmon juice on the surface of the fabric was gradually increased as the padding times of dyeing. And cotton fabrics were dyed evenly with persimmon juice by padding mangle.

• Physical Therapy Rehabilitation Science
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• v.8 no.3
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• pp.141-145
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• 2019

Objective: The purpose of this study was to compare walking conditions (straight line and curved path) on walking patterns in persons who had experienced hemiplegic stroke and to determine whether if they adapt their walking pattern and performances according to changes in environmental conditions. Design: Cross-sectional study. Methods: Forty-four hemiplegic stroke survivors participated in this study. This study measured walking performance in three different walking conditions, such as straight walking, the more-affected leg in the inner curve walking, and less-affected leg in the inner curve walking conditions, and a 2-dimentional gait analysis system was used as a primary measurement. This study also measured secondary clinical factors including the Timed Up-and-Go Test, the Trunk Impairment Scale, and the Dynamic Gait Index. Results: After analyzing, cadence and step length of the less-affected side, stride length in the more-affected side, and stride length in less-affected side were significantly different among the three different walking conditions in this study (p<0.05), but other temporospatial parameters were not significant. Cadence was the largest in the straight walking condition. Step length in the less-affected side, stride length in the more-affected side, and stride length in less-affected side were also the longest in the straight walking condition. Conclusions: The results of the study suggest that hemiplegic stroke survivors show walking adaptability according to changes in walking demands and conditions, and moreover, cadence and step and stride lengths were significantly different between straight and curved walking conditions.

• Journal of Plant Biology
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• v.16 no.3_4
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• pp.17-34
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• 1973

The physico-chemical factors, the distribution of chlorophyll and the primary production of the lakes Hwajinpo, Yongrangho, Chunchonho, Uiamho, Soyangho and Changjamot have been studied in order to make ecological comparison among these lakes during summer stagnation period of August to September of 1973. On the basis of the characteristics of these lakes, the lake types have been discussed. Thermocline is observed at 3-4m zone in the lake Changjamot and 4-5m zone in the lake Yongrangho. In the case of lake Hwajinpo and impoundments, the distinct thermal stratification is not observed at the summer stagnation period. As to vertical distribution of dissolved oxygen, a positive heterograde curve is obtained in the lakes Hwajinpo and Yongrangho. In the lake Changjamot the typical clinograde curve and the oxygen depletion in hypolimnion are observed. In the case of impoundments, however, the orthograde curve is observed in the lakes Chunchonho and Uiamho. While in the lake Soyangho, any stratification of the disssolved oxygen is not found. In the brackish lakes, such as lakes Hwajinpo and Yongragho, the salinity of hypolimnion is found to be much higher than that of epilimnion. In the lake Hwajinpo, the salinity of hypolimnion is exhibited 32.7$\textperthousand$, which is nearly the same as sea water. The distribution of nitrogenous compounds and phosphates is found to be high in the lake Changjmot. The silicate is also found in high concentration in the lake Chunchonho, and the distribution of nutrients in the brackish lakes is generally low. As to the vertical distribution of chlorophyll level, the lake Changjamot shows a stratum type and the brackish lakes L-type stratification. In the impoundments, lakes Chunchonho and Uiamho appear to be homogeneous type. Seasonal variation of chlorophyll level in the lake Changjamot is examined from January to September 1973. The vertical distribution of chlorophyll during the period of circulation from January to April is homogeneous type and is stratum type thereafter. The maximum chlorophyll level is 277.4mg/$m^2$ on June 23 and the pattern of seasonal variation of chlorophyll level is comparable to the type of eutrophy. The horizontal distribution of chlorophyll level is studied in the brackish lakes, Hwajinpo and Yongrangho. The pattern of distribution is found to be an irregular type. On the basis of measurements of primary production by means of the carbon-14 method and the distribution of chlorophyll level, it is concluded that the interior part of the lake Hwajinpo and Changjamot are eutrophic and the exterior part of the lake Hwajinpo, lake Yongrangho and the impoundments, lake Uiambo and Soyangho are mesotrophic.

• The Korean Journal of Pain
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• v.36 no.1
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• pp.113-127
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• 2023

Background: Resting-state functional connectivity (rs-FC) may aid in understanding the link between painmodulating brain regions and the descending pain modulatory system (DPMS) in fibromyalgia (FM). This study investigated whether the differences in rs-FC of the primary somatosensory cortex in responders and non-responders to the conditioned pain modulation test (CPM-test) are related to pain, sleep quality, central sensitization, and the impact of FM on quality of life. Methods: This cross-sectional study included 33 females with FM. rs-FC was assessed by functional magnetic resonance imaging. Change in the numerical pain scale during the CPM-test assessed the DPMS function. Subjects were classified either as non-responders (i.e., DPMS dysfunction, n = 13) or responders (n = 20) to CPM-test. A generalized linear model (GLM) and a receiver operating characteristic (ROC) curve analysis were performed to check the accuracy of the rs-FC to differentiate each group. Results: Non-responders showed a decreased rs-FC between the left somatosensory cortex (S1) and the periaqueductal gray (PAG) (P < 0.001). The GLM analysis revealed that the S1-PAG rs-FC in the left-brain hemisphere was positively correlated with a central sensitization symptom and negatively correlated with sleep quality and pain scores. ROC curve analysis showed that left S1-PAG rs-FC offers a sensitivity and specificity of 85% or higher (area under the curve, 0.78, 95% confidence interval, 0.63-0.94) to discriminate who does/does not respond to the CPM-test. Conclusions: These results support using the rs-FC patterns in the left S1-PAG as a marker for predicting CPM-test response, which may aid in treatment individualization in FM patients.

• Journal of The Korean Astronomical Society
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• v.50 no.3
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• pp.41-49
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• 2017

We conduct BVRI and R band photometric observations of asteroid (5247) Krylov from January 2016 to April 2016 for 51 nights using the Korea Microlensing Telescope Network (KMTNet). The color indices of (5247) Krylov at the light curve maxima are determined as $B-V=0.841{\pm}0.035$, $V-R=0.418{\pm}0.031$, and $V-I=0.871{\pm}0.031$ where the phase angle is $14.1^{\circ}$. They are acquired after the standardization of BVRI instrumental measurements using the ensemble normalization technique. Based on the color indices, (5247) Krylov is classified as a S-type asteroid. Double periods, that is, a primary period $P_1=82.188{\pm}0.013h$ and a secondary period $P_2=67.13{\pm}0.20h$ are identified from period searches of its R band light curve. The light curve phases with $P_1$ and this indicate that it is a typical Non-Principal Axis (NPA) asteroid. We discuss the possible causes of its NPA rotation.