• Journal of Korean Institute of Industrial Engineers
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• v.29 no.3
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• pp.197-205
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• 2003

Many people get plenty of information from World Wide Web, and the study of the factors that affect on reading task on web browser is presenting important issue. But domestic studies on legibility of Korean on web environment were relatively poor and the study about suitable text layout for skimming wasn't carried out also. At this point, this study was performed to investigate the effects of two types of reading, three levels of line length, and three levels of interlinear spacing on comprehension and reading rate when subjects read the materials on web browser. Reading speed, error rate, subjective preference and SACL(Stress and Arousal Checklist) evaluation were measured to evaluate the effects. Eighteen volunteer subjects participated in eighteen web document sessions with two different reading types, three different line lengths, and three different interlinear spacings. Statistical results from objective and subjective evaluations indicate that 50 characters per line of line length and 100 percents of interlinear spacing improved reading rate, overall error rates were reduced when reading normally, and SACL measures were increased at fast reading type. Consequently, in order to design text layout to retrieve information in WWW environment effectively, just applying guidelines of traditional printed material is not proper. Therefore, it is effective to consider reading type, line length, and interlinear spacing. Implications of these results and suggestions for the further study are also addressed.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.191-195
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• 1997

This study was conducted to obtain the basic information on setting up selection procedure using seedling characteristics in Angelica gigas Nakai lines. Morphological characteristics of the seedlings including height, leaf and petiole length among lines tested showed difference significantly, meaning that earlier selection was possible. Bolting rate at maturity ranged from 0.6 to 74.6% and root yield did from 350 to 3,893kg/ha. Root yield was increased in the lines with below 5% bolting rate. Heritabilities of petiole length, seedling height and leaf length in seedling stage bolting rate and root yield were high, while those of leaf length, root diameter and root length were relatively low. Bolting rate at maturity was positively correlated with seedling height, leaf length, leaf width, petiole length and number of leaves. A highly significant negative correlation was showed between root yield and seedling height, leaf length and width, petiole length, number of leaves, root length or bolting rate. From the above results the selection markers were found to be height, leaf length and petiole length in seedling stage.

• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.261-267
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• 2009

The purposes of this article is to analyse how market competition of credit card company affect price(interest rate) and survival length of card users. This paper uses individual account data from a large Korean credit card company during the periods from 2002 to 2006. The findings of our study are as follows. First, market competition of credit card company have a negative effect with interest rate of credit card. Second, market competition of credit card company have a affirmative effect with survival length. Finally, The effect of Increasing delinquency rate due to price increase is smaller than decreasing delinquency rate due to extending survival length.

• Fibers and Polymers
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• v.2 no.1
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• pp.140-143
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• 2001

To better understand the formation of necking in drawing processes of fibers, strain distributions during drawing processes have been analyzed. For simplicity, one-dimensional incompressible steady flow at a constant temperature was assumed and quasi-static model was used. To describe mechanical properties of solid polymers, non-linear visco-plastic material properties were assumed using the power law type hardening and rate-sensitive equation. The effects of various parameters on the neck formation were matematically analyzed. As material property parameters, strain-hardening parameter, visco-elastic coefficient and strain-rate sensitivity were considered and, for process parameters, the drawing ratio and the process length were considered. It was found that rate-insensitive materials do not reach a steady flow state and the rate-sensitivity plays a key role to have a steady flow. Also, the neck formation is mainly affected by material properties, especially for the quasi-static model. If the process length changes, the strain distribution was found to be proportionally re-distributed along the process line by the factor of the total length change.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.154-155
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• 2022

In this study, propose a plan to efficiently utilize CGS, a by-product generated from IGCC, as a mixed fine aggregate for concrete. The effect of the premixed cement types and CGS replacement rate on the overall characteristics and length change rate of concrete was analyzed. As a result of the analysis, the effect of CGS was found to be insignificant, and the effect of cement was found to be dominant.

• Journal of Environmental Science International
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• v.22 no.7
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• pp.895-903
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• 2013

This study analyzed on characteristics of the ground-water capture zone in coastal areas and mid-mountainous area according to pumping rate. For this study, it targeted Jejudo island where is the volcanic island. To analyze, MODFLOW model and MODPATH model, which are the ground-water flow analysis models, were used. As a result of research, the following conclusions could be obtained. As a result of analyzing influence of a change in pumping time upon length of capture zone, the length of capture zone in coastal area was indicated to be greater in the changing ratio compared to the length of capture zone in mid-mountainous area. Next, in the coastal area, the pumping rate and the capture-zone length are changing similarly. However, in mid-mountainous area, the length of capture zone was indicated to grow when the pumping rate comes to exceed 1,500m3/day. As a result of analyzing influence of a change in pumping time upon capture area, the tendency of a change in the area was indicated similarly in coastal areas and mid-mountainous area. Especially, it could be known that the larger pumping rate leads to the more definite increase in tendency to a change in capture area. Based on this study, it was allowed to be possibly used in the suitable pumping rate in coastal areas and mid-mountainous area of the volcano island in the future. A follow-up research is judged to necessarily analyze the influence of tubular-well group upon capture zone by additionally analyzing a change in capture zone targeting the concentrated tubular well.

• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.27-35
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• 2015

We analyze an M/G/1/K queueing system with queue-length dependent service and arrival rates. There are a single server and a buffer with finite capacity K including a customer in service. The customers are served by a first-come-first-service basis. We put two thresholds $L_1$ and $L_2$($${\geq_-}L_1$$ ) on the buffer. If the queue length at the service initiation epoch is less than the threshold $L_1$, the service time of customers follows $S_1$ with a mean of ${\mu}_1$ and the arrival of customers follows a Poisson process with a rate of ${\lambda}_1$. When the queue length at the service initiation epoch is equal to or greater than $L_1$ and less than $L_2$, the service time is changed to $S_2$ with a mean of $${\mu}_2{\geq_-}{\mu}_1$$. The arrival rate is still ${\lambda}_1$. Finally, if the queue length at the service initiation epoch is greater than $L_2$, the arrival rate of customers are also changed to a value of $${\lambda}_2({\leq_-}{\lambda}_1)$$ and the mean of the service times is ${\mu}_2$. By using the embedded Markov chain method, we derive queue length distribution at departure epochs. We also obtain the queue length distribution at an arbitrary time by the supplementary variable method. Finally, performance measures such as loss probability and mean waiting time are presented.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1534-1539
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• 2004

This experiment has been carried out to measure the process of droplet formation between water phase fluid(PVA 3%) and organic phase fluid(oil) and vector fields measured by a Dynamic Micro-PIV method in the inside of a droplet while generated. Droplet length controlled by changing flow rate conditions in microchannel. Water-in-oil(W/O) droplets successfully generated at a Y junction and cross microchannel. But oil-in-water(O/W) droplets could not be formed at a Y junction microchannel. That is, PVA 3% flow could not be detached from the PDMS surface and ran parallel with oil flow. When PVA 3% flow rate was constant, droplet length and time period decreased as oil flow rate increased, but droplet frequency increased. When PVA 3% and oil flow rate ratio was constant, droplet length and time period decreased as flow rate increased, but droplet frequency increased. All that case, Standard deviation of droplet formation have less than 5% at averaged droplet length and regular-sized droplets were reproducibly formed.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.5
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• pp.826-841
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• 1995

This study is concerned with the functional utility of movement in sleeve from an ergonomic viewpoint. Experiments were carried out which include 43 upper extremity segments, 21 motions and 35 female subjects. The major conclusions of the study are. 1. The expansion rate of upper extremity was higher in length than in circumference mesurements. The amounts of expansion were, especially high (more than 60mm) for inner arm length, axillary arm circumference, and outer arm length. Therefore, a lot of ease is necessary for these parts. On the other hand, armhole circumference, forearm circumference, and wrist circumference had low rates of expansion. The sleeve cap length was also contracted in all motions. 2. The expansion rate and the range of expansion and contraction were higher in the upper arm than in the forearm. The main points of expansion were the axillary and elbow parts. The segment of maximum expansi (rate of 44.8%) was Iii of axillary parts. As the body surface expands mainly in some segments, it is desirable to allow ease to the main segments of expansion. 3. In a basic sleeve, necessary ease was lacking in the measurements for outer arm length and axillary arm circumference, while it was too large in armhole circumference, forearm circumference, wrist circumference, and sleeve cap length. Therefore, a basic sleeve is inadequate as a functional sleeve for hard work in point of functional utility of movement. Wider application of these findings would lead to an improvement in the comfort of workers.

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.277-283
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• 1993

In the present study, observations were made on the life-history of Lymnaea viridis under laboratory conditions, involving incubation period of the eggs and their hatching rate, shell length of the newly hatched snails, sexual maturity, size of the snails when the snail produced the first egg-mass, the number of eggs in each egg-mass, egg-laying, ovipostion, growth rate of the snails, and longevity of the snail. At temperatures between $19.8^{\circ}C$ to $22.5^{\circ}C$, incubation period of the eggs occupied 10~12 days, and after beginning of hatching, all young snails emerged completely from the egg-mass within 5 days. The hatching rate was 88%. The average shell length of the newly hatched snails was about 0.064cm. The rate of growth was extraordinarily rapid under good laboratory conditions. When two snails were reared in one culture vessel($20{\times}15{\times}5cm$) with blue-green algae at about $22^{\circ}C$, snail growth was optimal, taking 37 days to reach 1.2cm in shell length. Sexual maturity reached in about 19 days. The size of the snails at sexual maturity was $0.78{\pm}0.05cm$ in length and $0.47{\pm}0.04cm$ in width. The first egg-masses produced were $0.59{\pm}0.22cm$ in length and $0.34{\pm}0.08cm$ in width, and contained 7~38 eggs. The eggs are usually laid in water. The egg-laying was affected by food and temperature. Snails fed with blue-green algae at about $22^{\circ}C$ produced larger egg-masses than the snails fed with fish food at about $26^{\circ}C$. Under conditions of continuous activity and growth, the maximum expectation of life appears to be 109~350(mean 230) days. And the shell length of snails at death were 1.39~1.64cm.