• Korean Journal of Soil Science and Fertilizer
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• v.50 no.1
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• pp.21-30
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• 2017

The study was performed to determine effective soil depth with crop type. Lysimeters, filled with three types of soils (sandy loam, loam and clay loam), were used. Effective soil depths for 25 cm, 50 cm, 75 cm, and 100 cm were considered for each soil. Six crops were investigated for plant height and yield, and rooting depths: Chinese cabbage, maize, lettuce, potato, red pepper, and soybean. Experiment was conducted at the National Institute of Agricultural Sciences in Suwon from 2012 to 2014. Effective rooting depth including 70% of root ranged from 19 cm to 29 cm for Chinese cabbage, from 24 cm to 38 cm for maize, from 17 cm to 24 cm for lettuce, from 27 cm to 32 cm for soybean, and around 50 cm and 30 cm for potato and red pepper. The maximum depth was 60 cm for soybean, 50 cm for Chinese cabbage, lettuce, and potato, and 75 cm for maize and red pepper. Each crop showed high yield in the treatment with soil depth over maximum rooting depth under all soils.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.683-689
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• 2012

This research was carried out to investigate the effect of installation spacing of subsurface drip irrigation pipe on the mineral content, nutrient uptake, yield of lettuce, water requirement for irrigation, and soil chemical properties in greenhouse cultivation. Semi-forcing and retarding culture were implemented in this experiment, with four treatments containing overhead spray irrigation and three subsurface irrigation lateral spacing intervals of 30, 40, 50 cm at a depth of 30 cm from soil surface, respectively. Each mineral content of lettuce grown under subirrigation system did not show significant difference between treatments, however the uptake of nutrients was lower at 50 cm-distance. The yield was largest in 30 cm-subirrigation (SI), followed by 40 cm-SI, overhead spray, and 50 cm-treatment. Water requirement for irrigation was highest in overhead spray, and it was in reverse proportion to the distance of irrigation pipes. $NO_3$-N content in the soil, at a depth of 10 cm, showed a higher value in 50 cm-SI, followed by 40 cm-SI, overhead spray and 30 cm-SI. Exchangeable K content was highest in 50 cm-SI, Mg was highest in 40 cm-SI, and Ca was lowest in 30 cm-SI. In conclusion, the lettuce yield was not different between 30 and 40 cm-SI, but water requirement for irrigation was lower as the distance of irrigation pipes was further. And it seems to be needed more precise research on this theme, because crop yield and the dynamics of soil minerals in subsurface irrigation can vary with the depth and distance of irrigation pipes, dripper, water flow depending on the soil texture, and plant response to soil minerals.

• Journal of radiological science and technology
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• v.29 no.4
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• pp.229-236
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• 2006

Purpose: This study was conducted to search for the type of technical error in DEXA(dual-energy X-ray absorptiometry) and the effect of error to measurement of BMD. Materials and Methods: The changes of BMD($g/cm^2$, T-score) by patients information(Age, Weight, Height, Manopause age) input error and Confirming ROI error were investigated. Using spine phantom, we canned 10 times by age(5, 10), weight(10, 20 kg), height(5, 10 cm), manopause age(5, 10) increase & decrease respectively. Scanning region(L-spine, femur, Forearm) of 10 patients was calculated by changing ROI respectively. Analysis of difference for mean(precision 1%) were carried out. Results: The error of patient information(Age, Weight, Height, Manopause age) was not changed differently. In confirming ROI, the BMD and T-score of L-spine involving T-12 was decreased to $0.063\;g/cm^2$, 0.3 and involving L-5 increased to $0.077\;g/cm^2$, 0.5. In narrowing 1 cm of vertical line of ROI, the BMD and T-score decreased to $0.006\;g/cm^2$, 0.1 and in 2 cm, $0.021\;g/cm^2$, 0.15, each. In hip ROI, Upper and left shift(0.5 cm) of line was not influenced BMD and T-score. In 0.5 cm lower shift(lesser trochanter below), the BMD and T-score increased $0.031\;g/cm^2$, 0.3 and in 1 cm $0.094\;g/cm^2$, 0.65, each. In forearm ROI, the BMD and T-score decreased $0.042\;g/cm^2$, 0.9 involving 1 cm lower wrist. And expanding 1 cm of vertical line, the BMD and T-score decreased $0.008\;g/cm^2$, 0.1 and in 2 cm, $0.021\;g/cm^2$, 0.3, each. The L-spine, hip, forearm ROI error was changed differently. Conclusion: There are so many kinds of technical error in BMD processing. Errors according to age, weight, height, manopause age did not influent to $BMD(g/cm^2)$ and T-score. There are mean differences BMD and T-score in confirming ROI. For the precision exam, in L-spine processing, L1-4 have to confirmed without shift of ROI vertical line. In hip processing, the ROI have to included greater trochanter, femur head and lesser trochanter. In forearm processing, the ROI have to included wrist, radius and ulnar.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.2
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• pp.155-162
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• 2016

The purpose of this study was to determine the walking imbalance using the EMG(electromyogram). To confirm the effectiveness of the proposed encoder and acceleration, EMG sensor based gait imbalance determination system. This experiment was carried out to evaluation with a healthy adult male to 10 people. The Encoder device is attached to the hip and knee joint in order to measure the gait signal. The Accelerometer sensors are attached on the ankle. The EMG sensors are attached on the vastus lateralis and anterior tibialis. SI(Symmetry Index) was used as an index for determining the gait imbalance. To confirm if the judgment has been made correctly, the heel, regarded as the cause of unbalanced ambulation, was adjusted from 0 cm to 6 cm with intervals of 1.5 cm. In the cases of the encoder and the EMG, the difference of 0 cm and 1.5 cm is determined into normal walk but the other difference is distinguished into gait imbalance. In the case of the accelerometer, the difference of 0 cm, 1.5 cm and 3 cm is determined into normal walk but the other difference is distinguished into gait imbalance.

• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.62-69
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• 2014

Since a government policy greatly affects markets and firms, an evaluation on government's policies is recognized as a critical issue. In Korea, two major policy plans on CM(Construction Management) include the Construction Industry Promotion Plan and the Construction Technology Promotion Plan from which Government's CM policies can be understood. The objective of the study is to analyze and discuss CM firm's perception and evaluation toward the Government's CM policies of the two plans based on the Gap analysis. The paper identified that the CM firms perceive that the Government's CM policies properly deal with key issues of the industry. However, they evaluate that the execution of the policies has been overall under-performed. As a way forward, the Government needs to improve on the execution plan and performance measurement rather than to develop new policy agenda.

• The Korean Journal of Community Living Science
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• v.28 no.1
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• pp.69-79
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• 2017

The purpose of this study was to compare fitting of the upper garment by brassiere cup size and types of bodice block. This study conducted a 3D virtual garment system by applying three types of bodice block (I, II, III) and experimental pattern of the bodice block to 3D avatars of four individuals with the following measurements: under bust circumference of 73.5 cm and bust circumferences of 83.5 cm, 86.0 cm, 88.5 cm, and 91.0cm. The results of the study were as follows. First, for 83.5 cm bust circumference (A Cup), appearance of the three types of bodice block (I, II, III) was appropriate. However, as bust circumference increased in size, shape became inappropriate. The depth and width of the armhole, within 15 cm and 11 cm, respectively, were found to be appropriate. In case of 91.0 cm bust circumference (D Cup), all three bodices (I, II, III) were inappropriate. Second, the results of the draft of the experimental patterns of the bodice block of bust circumference measuring 83.5 cm, 86.0 cm, 88.5 cm, and 91.0 cm in the 3D avatars of the four individuals revealed similarities in the frontal view of the silhouette in the four avatars; in the case of the lateral view of the silhouette, lateral width grew wider as bust circumference of the silhouette became larger, but the shape of armhole showed no changes. The depth of the armhole showed little changes from 15.1 cm to 15.22 cm, and the height of sleeve (armscye depth 13.6 cm within +2 cm) remained similar. The difference in width of the armhole from 11.26 cm to 11.37 cm was rather small. The width of the upper sleeve (8.97 cm) seemed to be appropriate as it remained within the 2-3 cm boundary.

• Journal of radiological science and technology
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• v.33 no.1
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• pp.61-66
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• 2010

In this paper we evaluated small field dose characteristics of exclusive cone fields versus square fields for stereotactic radiosugery (SRS) which is based on linear accelerators (LINAC). For this test, we used a small beam detector (stereotactic fields detector : SFD) with a 6 MV photon beam and a water phantom system (IBA, Germany). Percentage depth dose (PDD) was measured for different field sets (cones : ${\Phi}1\;cm$, ${\Phi}2\;cm$, ${\Phi}3\;cm$ ; square fields : $1{\times}1\;cm^2$, $2{\times}2\;cm^2$, $3{\times}3\;cm^2$) at a source skin distance (SSD) of 100 cm. We measured the point depths at 1.5 cm, 5 cm, 10 cm, 20 cm, and 30 cm. The output factors were measured under the same geometrical conditions of the PDD and normalized at the maximum dose depth. To analyze the penumbra, we measured the dose profile with 95 cm of SSD, 5 cm of depth for each field sizes (${\Phi}1\;cm$, ${\Phi}3\;cm$, $1{\times}1\;cm^2$, and $3{\times}3\;cm^2$) using SFD. We obtained the values for every 1 mm interval in the physical field (90%) and 0.5 mm interval in the penumbra region (20 to 80%). The PDD variation of exclusive cones and square fields were 4.3 to 7.9% lesser than the standard field size ($10{\times}10\;cm^2$. The variation of PDD was reduced while the field size was increased. To compare the beam quality, we analyzed the $PDD_{20,10}$ and the results showed under the 1% of variations for all experiments except for ${\Phi}1\;cm$ cone and $1{\times}1\;cm^2$ fields. Output factors of exclusive cone were increased 3.1~4.6% than the square fields, and the penumbra region of exclusive cone was reduced 20% as compared to the square fields. As the previous researches report, it is very important for SRS and SFD that precise dosimetry in small beam fields. In this paper, we showed the effectiveness of exclusive cone, compared to square field. And we will study on the various detector characteristics for small beam fields.

• Journal of The Geomorphological Association of Korea
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• v.20 no.3
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• pp.95-107
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• 2013

In order to examine the temperature regime responsible for periglacial processes, air and ground temperatures were monitored from October 2010 to May 2011 at a subalpine bare patch (1,710m asl) of Mt. Halla. Four thermistor sensor probes were installed at 55 cm above a ground surface and depths of 2 cm, 10 cm, and 20 cm, respectively. A mean air temperature is $-0.1^{\circ}C$, while mean ground temperatures are $1.8^{\circ}C$ at 2 cm, $2.6^{\circ}C$ at 10 cm and $3.2^{\circ}C$ at 20 cm deep. A mean monthly ground temperature at 2 cm deep demonstrates below $0^{\circ}C$ successively from January to March, while those at 10 cm and 20 cm deep show no sub-zero temperature. A total of 72 freeze-thaw cycle was observed in air temperature. However, the numbers in ground temperature reduced into 17 at 2 cm, 8 at 10 cm, and 3 at 20 cm deep. The cycles of air temperature and ground temperature at 2 cm deep mostly fluctuated diurnally, while those of ground temperature at 10 cm and 20 cm deep exhibited a several-daily oscillation. Snow cover over 55 cm high remained from January to early April, and it seemed to disappear completely on April 16. A seasonal frost of at least 2 cm thick was formed on late December and the isotherm of $0^{\circ}C$ descended slowly into 10 cm deep on late March to early April due to the insulating snow cover. It showed the maximum freezing depth of 20 cm on April 7 to 14 and then thawed rapidly so that the frozen ground did not longer after April 17. Periglacial processes are predominant during a freezing period than a thawing period when the ground surface is still covered with snow. The periglacial mass movement in the subalpine zone of Mt. Halla is mainly generated by frost creep in terms of the occurrence depth of diurnal freeze-thaw cycle and the maximum freezing depth of ground.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.280-291
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• 2023

Purpose: As fire accidents happen at the production and storage sites of superabsorbent polymers for convenience of daily life, an experimental study was conducted to secure basic data to establish practical preventive measures against them. Method: The sample container (20cm width × 20cm length) was made into a rectangular cuboid with the heights of 3cm, 5cm, 7cm, and 14cm, respectively, to allow access to the infinite flat plane. The front and back of the container were covered with a 300-mesh stainless steel mesh for one-dimensional heat transfer. The sample container was placed in the center of the thermostatic bath, which was heated to a predetermined temperature by setting the thermostat program in advance, and it was determined to be 'ignited' when the central temperature of the sample rose by more than 20℃ above the set temperature, and "unignited" when it was maintained at an approximate value of the set temperature. Result: The critical autoignition temperature was calculated to be 217.5℃ when the height of the sample container was 3 cm, 212.5℃ when it was 5 cm, 202.5℃ when it was 7cm, and 187.5℃ when it was 14cm. The ignition induction time to reach the maximum temperature was 34hours for 3cm, 76hours for 5cm, 143hours for 7cm, and 318hours for 14cm. Conclusion: ① As the size of the container increased, the autoignition temperature decreased and the induction time to reach the maximum temperature increased. ② An apparent activation energy was calculated to be 44.92kcal/mol, with a correlation of 96.93%.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.13-18
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• 2008

The BTL and CM are main issues in Korea construction industry lately. The BTL applying CM is sufficient to have interest in terms of combination of BTL and CM. OO Cultural and Welfare Complex Town construction was the first cultural and welfare facility with the BTL applying CM. Because application of CM to the BTL project is at the early stage, there are many problems under the progress such as administration procedure from misunderstanding of the BTL and lack of communication between supporting Dept. and management Dept. This article focuses on those problems and advantages of CM services including negotiation, schedule management and cost management for the better CM service in the BTL project in the future.