• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.217-218
• /
• 2012

• Journal of The Korean Society of Agricultural Engineers
• /
• v.56 no.4
• /
• pp.69-75
• /
• 2014

We investigated flood control capacity of 484 agricultural reservoirs with storage capacity of over 1 million $m^3$ in South Korea. In general, agricultural reservoir secures flood control capacity by setting up limited water level during flood season from late June to mid-September. The flood control capacity of an agricultural reservoir during flood season can be divided into stable flood control capacity during non-flood season, stable flood control capacity associated with limited water level, and unstable flood control capacity associated with limited water level. In general, the flood control capacity significantly (P < 0.001) increased with reservoir capacity irrespective of type of spillway. The unstable flood control capacity accounted for about 20 % of reservoir capacity in the uncontrolled reservoirs. The study reservoirs showed flood control capacity of 0.60-65 billion (B) $m^3$ and stable flood control capacity of 0.43-47 B $m^3$, depending on the upper and lower limited water levels during the flood season. The stable flood control capacity of the gated reservoirs (0.29-0.33 B $m^3$) was about two times than that of reservoirs with uncontrolled spillways (0.14 B $m^3$). The ratios of stable flood control capacity to reservoir capacity for agricultural reservoirs range from 21 to 23 %, similar to that for Daecheong multipurpose dam. Moreover, the reservoirs with over 100 mm ratio of flood control capacity to watershed area accounted for 38 % of total gated reservoirs. The results indicate that many agricultural reservoirs may contribute to controlling flood in the small watersheds during the flood season.

• Journal of the Korean Society of Physical Medicine
• /
• v.8 no.3
• /
• pp.361-368
• /
• 2013

PURPOSE: The purpose of this study was to investigate the comparison of balance on Stable Ankle(SA), Instability Ankle(IA) using Cumberland Ankle Instability Tool(CAIT). METHODS: Total 54(SA: 27, IA: 27) subjects were volunteered to participate in the study. SA can be defined CAIT score ${\geq}28$, with no history of injury to ankle. IA can be defined persisting symptoms of giving way and ${\leq}24$ on the CAIT after ankle sprain. the balance measured using Biodex Balance System$^{(R)}$(BBS). BBS instability protocols used static, dynamic balance level less stable(2), moderate stable(4) and level more stable(8). RESULTS: There were significant differences at overall, Anterior-Posterior(AP), Medial-Lateral(ML) of static balance, dynamic balance level 2, 4. The dynamic balance level 8 found significant difference at ML, but not found significant differences at overall, AP. CONCLUSION: We suggest that CAIT is acquired more exact information for IA intervention, as balance measured.

• Journal of The Korean Society of Integrative Medicine
• /
• v.6 no.3
• /
• pp.59-71
• /
• 2018

Purpose : The purpose of this study was to compare the effects of ankle balance training on unstable and stable surfaces to discover on which surface the proprioception, balance and muscle strength of obese middle aged women improves more. Method : Thirty obese middle-aged women were randomly recruited and divided into two groups (training on an unstable surface, training on a stable surface). The subjects in each group participated in the training for six weeks, three times per week for 30 minutes each session. Proprioception was measured using Dualer IQ digital inclinometer; sway length (SL) and sway area (SA) of center of pressure, and limit of stability (LOS) were measured for balance; muscle strength before and after the training was measured using manual muscle testing. Results : There were significant improvements in the subscales of the proprioception, balance and muscle strength in those who participated in ankle balance training on the unstable surface, and in those who participated on the stable surface. However, before and after the intervention, there were no differences between those who had the balance traning on the unstable surface and those who had the balance traning on the stable surface. Conclusion : Unstable and stable surface ankle balance training are both effective in improving the proprioception, balance and muscle strength of obese middle-aged woman.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.10 s.113
• /
• pp.929-934
• /
• 2006

In the paper, we suggest a simpler synthesis technique for capacitively-coupled match circuit(CCMC) which have a function of DC block and impedance matching simultaneously, and introduce a stability margin analysis technique for designing microwave amplifier under conditionally stable state. Stability margin analysis is used to determine optimum match point that ensure maximum gain under the given stability margin. It can reduce time consuming work for selecting match points in the conditionally stable state. Also, suggested miniaturization scheme of matching network is distinguished from previous work with respect to reducing deterministic parameters for CCMC synthesis. To verify utility of suggested method, 24 GHz gain block is fabricated under conditionally stable state using an internal thin-film fabrication process, Measured results show a stable gain of 10 dB and flatness of 1 dB, which is well coincident with simulated one.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.8
• /
• pp.3587-3593
• /
• 2011

This study was to investigate the balancing and clinical abilities using stable and unstable surface of stroke patients who surface changes in balance of body. The subjects of this study were 30 stroke patients(16 males and 14 females). They were separated into two groups and did balance reinforcing exercise on stable and unstable surfaces for five times a week for six weeks. To evaluate their balancing ability, they performed functional standing balance test, functional forward arm stretching test. performance-oriented mobility assessment was performed. The balancing exercises were modified from preceding studies and consisted of 6 difference exercises. The functional standing test with open and close eyes and performance-oriented mobility assessment, the unstable surface exercise group and the stable surface exercise group improved significantly. The forward arm stretching test was the unstable surface exercise group improved. This study found that the balancing exercise on unstable surface was more effective than on stable surface for stroke patients. Thus, exercise on unstable surface has more positive effects on the improvement of balancing abilities of stroke patients.

• Journal of the Korean Chemical Society
• /
• v.54 no.3
• /
• pp.275-282
• /
• 2010

2-Fluorocyclopropanemethanol and 2-chlorocyclopropanemethanol have been studied with MP2 and B3LYP methods with 6-311++G(d,p) basis set. The optimized structures show several stable conformers. The most stable conformer show the possibility of intramolecular hydrogen bonding, but the distance between $H{\cdots}F$, or $H{\cdots}Cl$ is longer than van der Waals radii and it may not be strong covalent bonding. Rather the second stable conformer has optimum structure for intramolecular hydrogen bonding but the energy of the conformer is 5 ~ 7 kJ higher than the most stable conformer. When the methanol group and the F or Cl atom have opposite direction, the conformers are less stable than the most stable conformer.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03a
• /
• pp.367-373
• /
• 2008

Spinning detonations propagating in a circular tube were numerically investigated with a one-step irreversible reaction model governed by Arrhenius kinetics. Activation energy is used as parameter as 10, 20, 27 and 35, and the specific heat ratio and the heat release are fixed as 1.2 and 50. The time evolution of the simulation results was utilized to reveal the propagation mechanism of single-headed spinning detonation. The track angle of soot record on the tube wall was numerically reproduced with various levels of activation energy, and the simulated unique angle was the same as that of the previous reports. The maximum pressure histories of the shock front on the tube wall showed stable pitch at Ea=10, periodical unstable pitch at Ea=20 and 27 and unstable pitch consisting of stable, periodical unstable and weak modes at Ea=35, respectively. In the weak mode, there is no Mach leg on the shock front, where the pressure level is much lower than the other modes. The shock front shapes and the pressure profiles on the tube wall clarified the mechanisms of these stable and unstable modes. In the stable pitch at Ea=10, the maximum pressure history on the tube wall remained nearly constant, and the steady single Mach leg on the shock front rotated at a constant speed. The high and low frequency pressure oscillations appeared in the periodical unstable pitch at Ea=20 and 27 of the maximum pressure history. The high frequency was one cycle of a self-induced oscillation by generation and decay in complex Mach interaction due to the variation in intensity of the transverse wave behind the shock front. Eventually, sequential high frequency oscillations formed the low frequency behavior because the frequency behavior was not always the same for each cycle. In unstable pitch at Ea=35, there are stable, periodical unstable and weak modes in one cycle of the low frequency oscillation in the maximum pressure history, and the pressure amplitude of low frequency was much larger than the others. The pressure peak appeared after weak mode, and the stable, periodical unstable and weak modes were sequentially observed with pressure decay. A series of simulations of spinning detonations clarified that the unsteady mechanism behind the shock front depending on the activation energy.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.10a
• /
• pp.367-373
• /
• 2008

Spinning detonations propagating in a circular tube were numerically investigated with a one-step irreversible reaction model governed by Arrhenius kinetics. Activation energy is used as parameter as 10, 20, 27 and 35, and the specific heat ratio and the heat release are fixed as 1.2 and 50. The time evolution of the simulation results was utilized to reveal the propagation mechanism of single-headed spinning detonation. The track angle of soot record on the tube wall was numerically reproduced with various levels of activation energy, and the simulated unique angle was the same as that of the previous reports. The maximum pressure histories of the shock front on the tube wall showed stable pitch at Ea=10, periodical unstable pitch at Ea=20 and 27 and unstable pitch consisting of stable, periodical unstable and weak modes at Ea=35, respectively. In the weak mode, there is no Mach leg on the shock front, where the pressure level is much lower than the other modes. The shock front shapes and the pressure profiles on the tube wall clarified the mechanisms of these stable and unstable modes. In the stable pitch at Ea=10, the maximum pressure history on the tube wall remained nearly constant, and the steady single Mach leg on the shock front rotated at a constant speed. The high and low frequency pressure oscillations appeared in the periodical unstable pitch at Ea=20 and 27 of the maximum pressure history. The high frequency was one cycle of a self-induced oscillation by generation and decay in complex Mach interaction due to the variation in intensity of the transverse wave behind the shock front. Eventually, sequential high frequency oscillations formed the low frequency behavior because the frequency behavior was not always the same for each cycle. In unstable pitch at Ea=35, there are stable, periodical unstable and weak modes in one cycle of the low frequency oscillation in the maximum pressure history, and the pressure amplitude of low frequency was much larger than the others. The pressure peak appeared after weak mode, and the stable, periodical unstable and weak modes were sequentially observed with pressure decay. A series of simulations of spinning detonations clarified that the unsteady mechanism behind the shock front depending on the activation energy.

• Korean Journal of Ecology and Environment
• /
• v.46 no.4
• /
• pp.471-487
• /
• 2013

This review paper was written to provide background information as well as future application for aquatic ecologists interested in using stable isotope. Stable isotope techniques has proved to be an extremely useful to elucidate a lot of environmental and ecological problems. Stable isotopes have been used as possible tracers to identify sources, to quantify relative inputs in a system. When utilized carefully, stable isotope tools provides apparent advantages for the scientists to find out the processes of material cycles in various environments and energy flows in natural ecosystems.