• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.280-280
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• 2017

In Korea, the average air temperature has been elevated twice faster than the average global warming. And the climate warming is characterized by the smaller rise of air temperature in summer and the greater rise of air temperature in spring and winter. Therefore, the number of frost-free days to determine the cultivation ability of crops has increased by more than 15 days in 10 years according to climate warming. This climate warming trend has extended and is projected to extend not only the sweet potato growing season but also the sweet potato early cultivating area to higher altitude and latitude region. This study was carried out to evaluate the possibility of sweet potato double cropping in the southern island area of Korea by assessing the growth and yield performance of sweet potato cultivated at extremely-early and -late time. We had performed at Yokji Island Yokji Island($E128^{\circ}$ 18' $N34^{\circ}$ 36'), a representative specified complex area of sweet potato cultivation in southern Korea. As the test varieties, the major cultivars of the this region, Shinyulmi and early hypertrophic cultivars, Dahomi were used. The prior cropping were planted with PE film mulching on March 30 and April 10, and harvested after 110 days. So the succeeding cropping were planted without PE film mulching on July 25 and August 5 according to the harvesting time of the prior sweet potato and harvested after 120 days. As a control, it was harvested on September 15, 120 days after planted on May 15. Each experimental plot had an area of 12 square meters consisting of 4 beds, and was planted one at a time at intervals of 25cm. We had investigated growth characteristics - main vine length, node number, branch number, total vine yield, and tuberous root characteristics - tuberous root number, average weight, starch value, and etc. After harvesting, we analyzed the economic effects by examining the postharvest quantity, the input labor, the management cost, and the income. The total yield of marketable products in prior and succeeding cropping was 46~70% higher than that of control. The average unit price of sweet potato was 36% higher than the conventional culture, and the gross income increased by 98%, but the operating cost increased by 83%, and the farm income increased by 103%. There are considerations such as the difficulty of enlargement of cultivation area due to lack of labor in limited space and the need for watering measures due to spring drought. However, if the area of application for sweet potatoes double system is increased by 10%, it can be used as a new cropping system.

• Journal of the Korean Geosynthetics Society
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• v.10 no.4
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• pp.123-130
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• 2011

In the precedent study it was presented that the comparison of thermal resistivity using various backfill materials including river sand regarding water content, dry unit weight and particle size distribution. Based on the precedent study, this study focused on developing the optimized backfill material that would improve the power transfer capability and minimize the thermal runaway due to an increase of power transmission capacity of underground power cables. When raw materials, such as river sand, recycled sand, crush rock and stone powder, are used for a backfill material, they has not efficient thermal resistivity around underground power cables. Thus, laboratory tests are performed by mixing Fly-ash, slag and floc with them, and then it is found that the optimized backfill material are required proper water content and maximum density. Through various experimental test, when coarse material, crush rock, is mixed with recycled sand, stone powder, slag or floc for a dense material, the thermal resistivity of it has $50^{\circ}C$-cm/Watt at optimum moisture content, and the increase of thermal resistivity does not happen in dry condition. The result of experiments approach the optimization of the backfill materials for underground power cables.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.295-305
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• 2013

Purpose: Recent research showed that total mixed ration (TMR) feeding for pigs improved the productivity and reduced feed cost and manure odor. An automatic TMR feeding system was developed for this study because the conventional feeder cannot deliver the TMR containing roughage. Methods: Conventional feeding systems and physical properties of TMR were surveyed, and performance tests of the conventional feeder were conducted to develop a TMR feeder. Based on the TMR feeder was developed and installed, driving, measuring weight, radio frequency identification (RFID) reading, and discharging test for feeding were conducted to ensure the performance. Results: Moisture content, density, and angle of repose of the TMR 1 (mixture of 30% cut IRG silage and 70% concentrates) were 31.6%, 387 $kg/m^3$, and $51^{\circ}$, respectively. Moisture content, density, and angle of repose of the TMR 2 (mixture of 45% concentrates, 30% cut IRG silage and by-products, 10% bean curd refuse, 10% others, and 5% fermenter) were 22.2%, 544 $kg/m^3$, and $50^{\circ}$, respectively. The coefficient of variation (C.V.) of conventional concentrate feeding were 1.9~4.1%, and C.V. of TMR containing 1~3% cut IRG roughage feeding by conventional feeder were 9~42%. The conventional disc type feeder was not suitable for TMR feeding because the supply unit was clogged. The C.V. of TMR 1 was 0.6~7.9% when 0.5~10 kg of the TMR supplied, and it was suitable for feeding grow-finish pigs and sows. On the contrary, the C.V. with TMR 2 was 28% when 0.5 kg of the TMR supplied, and it was not suitable for feeding sows. Conclusions: The TMR feeder developed in this study was suitable for feeding grow-finish pigs because the feeder performed stably with over 5.0 kg feed. However, the feeder showed a lack of accuracy for feeding sows because the amount of each feed was more than 0.5 kg per a feeding. Therefore, the improvement of outlet structure for accurate feeding is needed for sow feeding.

• The Journal of Engineering Geology
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• v.17 no.3
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• pp.425-434
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• 2007

In this paper, the stability standards of slopes reclaimed by soils mixed with stone dust were proposed to manage the stone dust as recovery soils. First of all, the mixed ratio between stone dust and natural soil is classified into 5 groups, and a series of soil test was performed in each group. As the results of tests, the shear strength and the maximum dry unit weight were increased in decrease of the mixed ratio of stone dust. On the basis of the investigation to the safety factor standards of embankment slopes in and outside the country, a slope stability rank of slopes reclaimed by mixed soils were divided into 3 stages such as unstable stage, attention stage and stable stage. The slope angle, the slope height and the mixed ratio with stone dust were proposed by the result of stability analysis of slopes reclaimed by mixed soils. As the result of slope stability analysis, the slope angle of 1 : 1.8 at the reclaimed slope should be constructed in case of the slope height of 10 m. Also, the slope angle of 1 : 1.8 and the mixed ratio of stone dust less than 50% should be constructed in case of the slope height of 15 m. The analysis result of reclaimed slope constructed inside the quarry is similar to that of reclaimed slope constructed on the open ground in same conditions of the slope angle, the slope height and the mixed ratio with stone dust. The proposed stability standards of slopes reclaimed by soils mixed with stone dust can be used practically at the quarrying site.

• The Journal of Engineering Geology
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• v.30 no.2
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• pp.185-198
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• 2020

High-density rapid expansion material is a method that increases the solid volume of injection materials due to hydration and foam reactions at the same time as spraying. It is an effective method for securing ground stability, restoring subsidence, and loading during construction of structures. In this regard, through the mechanical experiments of injection materials, the stability of the foundation ground of the structure and the effect of increasing the endurance using site construction were analyzed. The results of the experiment showed that the unit weight of soil decreased by 10.5% after injection of the filling material, and the allowable support for the structure was deemed safe, and the subsidence by each section after ground improvement was determined to be safe at 2.28, 1.55 and 0.46 cm, respectively, with an acceptable subsidence of less than 5 cm. After the field test, five inclinometers were installed on the top floor of the target building to measure the displacement of the X and Y axes. As a result of the measurement, no displacement related to the phenomenon of inequality or subsidence cracks of the structure was measured for about 16 months (509 days) after construction. This can be judged to be a sufficient increase in the stability of the ground after the injection of rapid expansion.

• Journal of Hospice and Palliative Care
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• v.7 no.2
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• pp.179-188
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• 2004

Purpose: The purpose of this study was to investigate the degree of fatigue and its related factors in cancer patients during chemotherapy. Methods: The subjects of this study consisted of 90 patients over 20 years old who were receiving chemotherapy at the injection room of the o.p.d. and ward admission care unit in a University hospital located in Gwang-ju city and data were collected from August 8th to October 2nd, 2002. Collected data were analysed using SPSS v 10.0. to obtain summary statistics for the descriptive analysis, t-test, ANOVA, pearson correlation, and multiple regression. Results: 1. Fatigue of the subjects was significantly correlated with physical distress score. and 6 items of subscale those were nausea, vomiting, anorexia, pain, and immobility, showed statistically significant correlation. 2. Fatigue of the subjects showed statistically significant differences according to a nap satisfaction. Fatigue of the subjects was significantly correlated with mood state, Also, all 5 items of subscale, which are those were anxiety, confusion, depression, energy, and anger showed statistically significant correlations. 3. Fatigue of the subjects showed statistically significant differences according to metastasis, chemotherapy cycle, post operation existence, post radiation therapy existence. There were significant negative correlation between fatigue and hematocrit and fatigue and weight change. There was no significant correlation between fatigue and spiritual well-being state. With the result to multiple regression, Immobility, Anorexia, Anger explained fatigue by, pain, and immobility showed statistically significant correlation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.62-69
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• 2012

This study investigates the engineering properties of the high strength concrete depending on dosages and types of shrinkage reduction agent. Test results showed that for the properties of fresh concrete, the addition of the conventional shrinkage reduction agent (SR) of 0.25% decreased slump flow up to 40% as compared with control concrete, whereas the addition of the emulsified waste cooking oil (EWCO) decreased slump flow of only 5% to 10%. Other properties of fresh concrete with the agents, namely air content, unit weight and setting time, were similar to the results of the control concrete. For the properties of hardened concrete, the compressive strength of the concrete with SR decreased at both early and later stage. However, the compressive strength of the concrete with EWCO was similar to the control concrete at early age, but decreased at later stage (up to 10% reduction at 28 days). For the effect of the agents on autogenous shrinkage of the concretes, the addition of EWCO decreased up to 33%, whereas that of SR decreased up to 29%. Hence, it can be said that the addition of EWCO in high strength concrete has an effect on reducing the autogenous shrinkage as compared with a conventional agent and only slight influence on the slump flow and air content of concrete. By taking all aspects of using EWCO, it is concluded that the optimum content of EWCO will be in the range of between 0.5% and 0.75%.

• Child Health Nursing Research
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• v.6 no.1
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• pp.32-50
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• 2000

A descriptive exploratory design was used in this study to evaluate the effects of sponge bathing on physiological(heart rate, heart period, vagal tone, oxygen saturation, respiration) and behavioral responses in newly born 40 preterm infants from intensive care unit of S University Hospital in Seoul. Data has been collected from October, 1997 to March, 1999. The infants were between 27-33 weeks gestational age at birth, and were free of congenital defects. The subjects entered the protocol when they were medically stable (determined by initiation of feeding and discontinuation of all respiratory support) but still receiving neonatal intensive care. The infants' physiologic parameters were recorded a 10 - minute before, during, and after bathing. Continuous heart rate data were recorded on a notebook computer from the infant's EKG monitor. The data were digitized off-line on software(developed by Lee and Chang in Wavelet program) which detected the peak of the R wave for each heart beat and quantified sequential R-R intervals in msec(i.e. heart periods). Heart period data were edited to remove movement artifact. Heart period data were quantified as : 1) mean heart period; 2) vagal tone. Vagal tone was quantitfied with a noninvasive measure developed by Porges(1985) in Mxedit software. To determine behavioral status, tools were developed by Scafidi et al(1990) were used. Collected data were analyzed with the SPSS program using paried t-test, ANOVA, and Pearson correlation. The result were as follow. 1. The results of the ANOVAs indicated that vagal tone were signifcantly lower during bathing than baseline and post-bathing. There were significant differences in heart period and heart rate levels across the bathing. But the mean oxygen saturations and respirations were no differences. Also, there were no significant differences on behavioral sign, motor activity, behavioral distress, weight changes, morbidity, and hospitalization period. 2. To evaluate the relation between vagal tone and subsequent parameters, the two groups (the high group had 19 subjects and low group had 21subjects) were divided by the mean baseline vagal tone. Vagal tone measured prior to bathing were significantly associated with respiration before bathing, vagal tone during bathing, and the magnitude of change in both vagal tone. But, other subsequent reactivities were no differences in two groups. 3. Correlations were also calculated between vagal tone and the subsequent physiological reactivities from baseline through after- bathing. Correlations were significant between baseline vagal tone and baseline heart rate, between baseline vagal tone and baseline heart period, between baseline vagal tone and oxygen saturation after bathing. In summary, the bathing in this study showed a stressful stimulus on premature infants through there was significance in the physiological parameters. In addition, our study represents the documentation that vagal tone reactivity in response to clearly defined external stimulation provides an index of infant's status.

• Child Health Nursing Research
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• v.21 no.1
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• pp.37-45
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• 2015

Purpose: In this study, a comparison was done of the extent of health-related quality of life (HRQoL) for preterm and fullterm children during early childhood, and factors affecting HRQoL in the early childhood of premature children were analyzed. Methods: Eighty mothers of children born prematurely and 83 mothers of children born at fullterm listed on two Internet cafes were sampled for this study. The major instrument used for the study was the TNO-AZL Preschool Quality Of Life (TAPQOL) questionnaire. Results: Total score for HRQoL in the premature group was 80.5 (${\pm}9.9$) and for the full term group, 85.0 (${\pm}8.3$), on a 100-point scale. A comparison of the premature group and full term group showed that the domains which scored relatively lower with respect to HRQoL included the stomach, motor function, anxiety, liveliness and communication. Among the factors that have an impact on HRQoL were 'length of stay in neonatal intensive care unit (${\geq}7$ days)' and 'birth weight (<1,000 gm)'. The explanation power of the model was 17%, which was statistically significant. Conclusion: These findings indicate that a differentiated premature infant follow-up program for children who are hospitalized over 7 days in NICU or weighed under 1,000g at birth is urgently needed.

• Tunnel and Underground Space
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• v.30 no.2
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• pp.164-179
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• 2020

Applying the limit state design method to geotechnical structures, accuracy and reliability of its design are mainly affected by parameters for geotechnical site characteristics, such as unit weight, Poisson's ratio, deformation modulus, cohesion and frictional angle. When the structures are located in weathered ground, especially, cohesion and frictional angle of ground are closely related with decision of parameters for structures' load and ground's resistance. Therefore, the accurate determination of these parameters, which are commonly obtained from field measurement, such as borehole shear test, are essential for optimum design of geotechnical structures. The 38 case studies, in this study, have been analyzed for understanding the importance of these parameters in designing the ground structures. From these results, importance of field measurement was also ascertained. With these evaluations, an apparatus for determining the strength characteristics, which are fundamental in limit state design (LSD) method, have been newly developed. This apparatus has an improved function as following the ASTM suggestion. Through the field application of this apparatus, the strong point of minimizing the possibility of error occurrence during the measurement has been verified and authors summarized that the essential parameters for LSD can be qualitatively obtained by this apparatus for determination of strength characteristics of weathered ground.