• Environmental Engineering Research
• /
• v.14 no.2
• /
• pp.111-119
• /
• 2009

A prototype GIS-based decision support system (DSS) was developed by using a database management system (DBMS), a model management system (MMS), a knowledge-based system (KBS), a graphical user interface (GUI), and a geographical information system (GIS). The method of selecting a dispersion model or a modeling scheme, originally devised by Park and Seok, was developed using our GIS-based DSS. The performances of candidate models or modeling schemes were evaluated by using a single index(statistical score) derived by applying fuzzy inference to statistical measures between the measured and predicted concentrations. The fumigation dispersion model performed better than the models such as industrial source complex short term model(ISCST) and atmospheric dispersion model system(ADMS) for the prediction of the ground level $SO_2$ (1 hr) concentration in a coastal area. However, its coincidence level between actual and calculated values was poor. The neural network models were found to improve the accuracy of predicted ground level $SO_2$ concentration significantly, compared to the fumigation models. The GIS-based DSS may serve as a useful tool for selecting the best prediction model, even for complex terrains.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.27 no.5
• /
• pp.114-119
• /
• 2000

This study was carried out to obtain fundamental information of growth response of ground cover plants under artificial light quality at indoor. Aglaonema 'Silver Queen', Hedera helix L., Hoya carnosa 'Tricolor' and Saintpaulia ionantha 'Frances' were examined under a 400lux light intensity consisted of Mercury lamp, True-lite lamp, incandescent lamp, dark-room and sunlight indoor condition. A data analysis were performed by GLM, Duncan's multiple range test and mean score with SAS program. Results of experiments are as follows; 1. A plant growth status was better showed under the True-lite lamp than sunlight. 2. A Saintpaulia ionantha flower color was responded in the first place, the deep pinkish red color of Saintpaulia ionantha flower was obtained under Mercury lamp and "True-lite lamp", "sunlight", and incandescent lamp were follow. Flower numbers of Saintpaulia ionantha after 60 days tended to decrease under every artificial light quality. 3. Leaf length and leaf width were increased under True-lite lamp, but most of plants was not significantly affected by artificial light quality. 4. A stem length of Hedera helix was increased the highest rank under sunlight also, one of artificial light, the highest increase rank was showed under incandescent lamp. 5. Chlorophyll content was highly increased under Mercury lamp, but was responded poor under incandescent lamp.

• Journal of International Academy of Physical Therapy Research
• /
• v.10 no.1
• /
• pp.1706-1710
• /
• 2019

Background: Despite frequent shoulder injuries of rotator cuff muscle of golfers by the result of overuse and poor swing mechanics, there is little research on shoulder specific rehabilitation exercises for injured rotator cuff muscle and golf swing Objective: To examined the effect of rehabilitation exercise for golfers on the X factor and ground reaction force (GRF) according to phase of the golf swing. Design: Crossover study Methods: The participants were 13 amateur golfers selected for a 4 week rehabilitation exercise for golfers. A rehabilitation exercise for golfers consisting of 5 steps and 4 items (sleeper stretch, full side plank, push up to plank, high plank knee unders) were applied to all participants. A three dimensional motion analyzer and force platform (SMART-E, BTS, Italy) were used to measure the X factor (angle between shoulder and pelvis at top of back swing) and GRF according to phase of the golf swing. All dependent variables were measured before and after exercise. The collected data was analyzed using the paired t test and SPSS 21.0. Results: The GRF had a statistically significant increase in the impact phase and ratio impact/weight after rehabilitation exercise for golfers (p<.05). The X-factor, GRF in top of back swing and finish were no significant differences between before and after exercise (p>.05). Conclusions: These results suggested that rehabilitation exercise for golfers was effective for increasing GRF in the impact phase and ratio impact/weight for amateur golfer.

• Journal of the Korean Geosynthetics Society
• /
• v.18 no.1
• /
• pp.91-101
• /
• 2019

Recently, small-scale excavation like ground cavity restoration and buried pipe replacement works are being carried out in urban area, in order to improve living convenience. This paper describes experiment results on the ground reinforcement method that can reduce the buried pipe damage, when the differential settlement occurred due to poor compaction of ground below the buried pipe. Plate load tests were conducted to evaluate a reinforcement effect of ground using concrete mat and expansion mat in the ground below the buried pipe. The results showed that the stress reduction ratio by concrete mat and expansion mat according to the surcharge load was about 46%~48% and 39%~42%, respectively. Therefore, the differential settlement of the buried pipe and the ground deformation below the buried pipes were reduced by the reinforcement effect of the concrete mat and expansion mat. This means that it is possible to prevent a buried pipe damage due to underground cavity and ground subsidence, if concrete mat and expansion mat are reinforced in the ground below the buried pipe or on the ground between the buried pipes.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.18 no.4
• /
• pp.4209-4217
• /
• 1976

The purpose of this thesis is to search for the determination method of pumping rates in the existing tube wells for irrigation. Pumping tests were carried out for the twelve test tube wells which were selected in the provinces of Kyounggi, Kangwon, Chungbuk and Chungnam. The depths, static water levels, pumping levels, drawdowns and yields of tube wells were measured in the pumping tests, and a centrifugal pump with 3 inches diameter, a 5 HP motor and a 90$^{\circ}$ V-notch were used in the pumping tests. The average coefficient of transmissibility calculated by Chow's and Jacob's methods is 0.0336 square meter per second, and the average pumping rate calculated by Thiem's, Smreker's, Brinkhaus' and Theis' formulae, is 919 cubic meter per day, Therefore, the ground water storage in the test areas is comparatively abundant. Correlation between pumping rates and depths of tube wells is not in existence. Also, correlation between pumping rates and the thickness of aquifer is not found in this experiment. This shows that the depths of some tube wells are deep and their thicknesses of aquifer are thick, but their ground water storages are poor, and that the depths of some tube wells are shallow and their thicknesses of aquifer are thin, but their ground water storages are abundant. It seems that the test tube wells are influenced by the peculiar characteristics that the ground water in the test areas is free ground water in alluvium layer closely related with surface water. As drawdown increases, pumping rate decreases, and as the coefficient of transmissibility increases, pumping rate also increases. Namely, there are negative correlation between pumping rate and drawdown, and positive correlation between pumping rate and the coefficient of transmissibility. Judging from the results of the pumping tests in these tests areas, the pumping rate calculated by the formula, {{{{ { Q}_{m } =Q { ( { { S}_{ m} } over { TRIANGLE S } )}^{ { 2} over {3 } } }}}} used traditionally, is likely to be higher than real pumping rates. The formula, {{{{ { Q}_{m } =Q { { H}^{ 2} } over { (2H- TRIANGLE S) TRIANGLE S} }}}} derived from Thiem's theory, is looked upon as the reasonable one to detemine pumping rates in the existing tube wells for irrigation.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.2
• /
• pp.43-52
• /
• 2010

Shield method is the tunnel boring method that propels a steel cylinder in the ground and excavates tunnels at once. After Marc Isambard Brunel started using the method for the Thames Riverbed Tunnel excavation in London, many kinds of TBM (Tunnel Boring Machine) developed and applied for the construction of road, railway, electricity channel, pipeline, etc. In comparison with NATM concept that allows to observe ground condition and copes with difficulty. The machine selected before starting construction is not able to be changed during construction in shield TBM. Therefore the machine should be designed based on the ground survey result and experiment, so that the tunnel might be excavated effectively by controlling penetration speed, excavation depth and cutter head speed according to the ground condition change. This research was conducted to estimate penetration depth, excavate speed, wear of disc cutter on Boondang Railway of the Han Riverbed Tunnel ground condition by TBM performance prediction models such as NTNU, $Q_{TBM}$, Total Hardness, KICT-SNU and compare the estimated value with the field data. The estimation method is also used to analyze the reason of poor excavation efficiency at south bound tunnel.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.9
• /
• pp.689-699
• /
• 2013

During extreme ionospheric storms, anomalous ionospheric delays and gradients could cause potential integrity threats to users of GNSS (Global Navigation Satellite System) augmentation systems. GNSS augmentation ground facilities must monitor these ionospheric anomalies defined by a threat model and alarm the users of safely-of-life applications within time-to-alerts. Because the ionospheric anomaly threat model is developed using data collected from GNSS reference stations, the use of poor-quality data can degrade the performance of the threat model. As the total number of stations increases, the number of station with poor GNSS data quality also increases. This paper analyzes the quality of data collected from Korean GPS reference stations using comprehensive GNSS data quality check algorithms. The results show that the range of good and poor qualities varies noticeably for each quality parameter. Especially erroneous ionospheric delay and gradients estimates are produced due to poor quality data. The results obtained in this study should be a basis for determining GPS data quality criteria in the development of ionospheric threat models.

• Journal of Environmental Science International
• /
• v.23 no.1
• /
• pp.81-88
• /
• 2014

In this study, one of the measures for the promotion of the growth of trees planted in poor drainage areas, which functionality pipe supplying oxygen in the soil, and promotes drainage, barren soil and poor drainage areas in planting design was to provide the basic data to compare the impact on the application of functionality pipe. The Zelkova serrata testing materials were selected, planted a total of 12 by three to four individual experiments were conducted. Growth measurements of the items Plot A > Plot C > Plot D > Plot B were excellent in the order of height, number of leaves, leaf width, and chlorophyll content, Plot A > Plot C > Plot D > Plot B was in good order of the growth of the length of the root-collar diameter, Plot C > Plot A > Plot B > Plot D in order rate of variation was good. This has adverse effects on plant growth, poor drainage planting base represents, promote drainage and oxygen supply technique can be applied good to the planting from Zelkova serrata growth based drainage is poor and barren presented as part of research to be done in the future include a means for promoting the growth of plants in soil, the planting design.

• Tunnel and Underground Space
• /
• v.27 no.6
• /
• pp.343-350
• /
• 2017

Amid increasingly saturated ground space, development of underground space has been booming throughout the world and excavation has been underway near the structure above or under the ground level. But the ground subsidence caused by improper or poor construction technologies, underground water leakage, sudden changes of stratum and the problem with earth retaining system component has been emerged as hot social issue. To deal with such problems nationwide, establishment of preventive and proactive disaster management and rapid restoration system has been pushed now. In this study, collection of the data on technology development trend to secure the underground safety was made, taking into account of internal change elements (changing groundwater level, damage to underground utilities, etc) and external change elements (vehicle load, earthquake and ground excavation, etc) during excavation. Amid the growing need of ground behavior analysis, ground subsidence evaluation technology, safe excavation to prevent ground subsidence and reinforcement technology, improvement of rapid restoration technology in preparation for ground subsidence and development of independent capability, this study is intended to introduce the technology development in a bid to prevent the ground subsidence during excavation. It's categorized into prediction/evaluation technology, complex detect technology, waterproof reinforcement technology, rapid restoration technology and excavation technology which, in part, has been in process now.

• Journal of the Korean GEO-environmental Society
• /
• v.24 no.1
• /
• pp.15-23
• /
• 2023

The grouting method is a method of construction for the purpose of waterproofing and reinforcing soft ground. When grout is injected into the ground, there are various types of penetration and diffusion of grout depending on the shape of the ground, the size of soil, the porosity, and the presence or absence of groundwater. the current situation. Therefore, in this study, to investigate the penetration performance of the grouting to conductive material, laboratory tests were performed on the addition of the conductive material. In the injection test, 0%, 3%, and 5% of the mixed water were added as conductive materials to the grout, and the original ground condition was composed of various types of ground composed of gravel and silica sand. Conductive grout is injected by pressure into the model ground using a dedicated injection device, and the injection time (t), pressure (p), flow rate (v) and injection amount (q) are measured, and the hardened body injected in the model ground is collected. Penetration performance was evaluated. In the results of the grout injection experiment, the amount of conductive material used and the grout injection rate showed an inverse relationship, and it was confirmed that the penetration pattern was changed according to the size of the soil particles in the model ground. The grout containing the conductive material has relatively good penetration into the ground and excellent strength and durability of the hardened body, so it was judged that it could be used as an additive for measuring the penetration range of the grout.