• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.05a
• /
• pp.892-896
• /
• 2001

Investigation is performed on the stability of nonlinear system under turbulent fluid motion modelled as white noise random process, which is a preliminary result in the course of research on the characteristic and nonlinear control of the stochastic system. Adopted physical model is beam-type structure with tip-mass and main base mass. The governing equation is derived via F-P-K approach in stochastic sense. By means of Gaussian Closure method infinite dynamic moment equations due to system nonlinearity is closed to finite one. At the best of authors' knowledge, it is the first trial to design nonlinear controller by using of sliding mode technique in stochastic domain and control performance and effect in stochastic domain is studied.

• Explosives and Blasting
• /
• v.33 no.2
• /
• pp.25-39
• /
• 2015

The common underwater rock removal methods involve underwater blasting and crane's chisel dropping impact method. From an environmental point of view, these methods cause ground vibrations and underwater noise. At the site for this study, a method of dropping heavyweight chisel is selected to remove the underwater bedrock near the ferry rack in the course of improving the cargo handling ability of the loading dock. A prediction formula for the vibration was obtained based on the measurement and evaluation of the vibrations caused by the chisel dropping impacts during the test droppings. The prediction formula was successfully applied to the main construction for securing the stability of the structure.

• Aerospace Engineering and Technology
• /
• v.3 no.1
• /
• pp.109-116
• /
• 2004

In a satellite time management system, the GPS-based clock synchronization technique[1] has the merits of precision time management by knowing the time difference or the error between the OBT(On Board Time) of the internal processors and GPS time every second. It can be realized employing the DPLL(Digital Phase Loop Lock) and FEP(Front End Processor) circuitry for the clock synchronization[2]. In this paper, a refined DPLL & FEP scheme is proposed to provide the precision, stability and robustness of the operation, which is to compensate the errors and noise of the GPS signal, and also to cope with the case when the GPS signal is lost due to several reasons. The simulation and HIL (Hardware In the Loop) test results using the FM(Flight Model) in the course of KOMPSAT-2(Korea Multi Purpose Satellite-2) design and development are illustrated to demonstrate the salient features of this methodology.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.6
• /
• pp.1646-1658
• /
• 2020

In order to investigate the changes in growth hormone, testosterone, blood lactate, double product, and pain, this study conducted intensive weight training and circuit weight training with 60% intensity of 1RM for 7 men who had more than 6 months of resistance exercise and then performed Underwater Walking and Underwater Sitting with underwater recovery. Growth hormone was high in all exercise forms and recovery methods in order of after exercise, after recovery, and after stability, and testosterone was high in order of after exercise, after recovery, and stability. Blood lactate was higher in all exercise forms and recovery methods in order of after exercise, after recovery, and after stabilization, and dynamic recovery after concentration resistance exercise was lower than static recovery. Double product was higher in all types of exercise and recovery methods in order of after-exercise, after-recovery, and stability. Muscle pain decreased in the order of exercise, recovery, 24 hours, 48 hours, and 72 hours in all exercise forms and recovery methods. In the water environment, dynamic recovery is considered to be more effective in improving muscle fatigue than static recovery.

• Journal of the Korean Geotechnical Society
• /
• v.20 no.3
• /
• pp.75-83
• /
• 2004

The Indiana Department of Transportation (INDOT) has permitted the use of Lime Kiln Dust (LKD) as a low-cost construction material in creating a workable platform for soil modification (not for soil stabilization) since the early 1990s on selected projects. However, the enhanced strength of soils with LKD has not been accounted for in the subgrade stability calculations in the design process. This study was initiated to evaluate how the lime kiln dust is a comparable material to hydrated lime. A series of laboratory tests were performed to assess the mechanical benefits of lime kiln dust in combination with various predominant fine grained soils encountered in the State of Indiana, such as A-4, A-6 and A-7-6. In the course of this study, several tests such as the Atterberg limits, standard Proctor, unconfined compression, CBR, volume stability, and resilient modulus were performed. As a result, mixtures of fine grained soils with 5% lime or 5% LKD substantially improve unconfined compressive strength up to 60% - 400%. CBR values for treated soils are in the range of 25 to 70 while those for untreated soils range from 3 to 18. In general, significant increase in resilient moduli of the soils treated with lime and LKD was observed. This indicates that lime kiln dust may be a viable, cost effective alternative to hydrated lime in enhancing the strength of fine grained soils.

• Journal of Oriental Neuropsychiatry
• /
• v.20 no.2
• /
• pp.85-99
• /
• 2009

Objectives : This study aimed to understand the influence of acupuncture on the human body by comparing changes within human bodies before and after people in normal health are treated with acupuncture at the acupoints HT7 and PC9, which are related to mental functions. Methods : The study was performed from January 3, 2008 to March 5, 2008 on 60 healthy males and females in their 20s. HRV, EEG, skin conductance response, respiration and peripheral skin temperature were measured for 5 minutes before acupuncture simulation was applied to the acupoints HT7 and PC9. During 20 minutes of acupuncture treatment, the same items were continuously measured to determine whether there had been any changes, and they were then measured for 5 minutes after the removal of the acupuncture needles in order to implement a comparative analysis. Results : 1. The HRV measurement showed that in the course of before, during and after acupuncture stimulation, heart rate, HF and HF norm decreased significantly (P<0.05) at HT7. LF, LF norm, and LF/HF ratio increased significantly (P>0.05), while heart rate, HF and HF norm decreased significantly (P<0.05) at PC9. 2. Skin conductance response increased significantly (P<0.05) at PC9 during and after the acupuncture simulation periods, compared with the pre acupuncture period. 3. the peripheral skin temperature increased significantly (P<0.05) both at HT7 and PC9 in the course of before, during and after acupuncture stimulation. 4. Compared with the pre-acupuncture period, respiration rate increased both at HT7 and at PC9 during and after the acupuncture simulation periods, but not in a statistically significance. 5. In the EEG measurement, when compared with the pre-acupuncture period at HT7, mid ${\beta}$ wave decreased significantly (P<0.05) during acupuncture treatment. Compared with the measurements during acupuncture treatment at PC9, low ${\beta}$ wave increased significantly (P<0.05) after the acupuncture needles were removed. Conclusions : When acupuncture treatment is applied at the acupoints HT7 and PC9, the activation of parasympathetic nerves decreases and the activation of sympathetic nerves increases in the HRV measurement. It was determined that PC9 makes the sympathetic nerves become highly activated in a skin conduction response. The effect of stability in the brain wave seemed to bo shown at HT7 than PC9.

• Korean Journal of Environment and Ecology
• /
• v.7 no.2
• /
• pp.118-134
• /
• 1994

This study was conducted to investigated the plant community structure and to revaluate the part of plant ecosystem on statement of environmental impact assessment in Muju resort golf course, Solch'on area, Tokyusan National Park. The actual vegetation was comprised of Pinus densiflora-Quercus mongolica-Q. serrata community(33.21%), Q. spp. community(27.30%), P. densiflora community(20.68%) and high mountain marsh(4.93%) etc., which communities were the major vegetation and the forest vegetation was came to being a peculiar to environmental condition. The degree of green naturality 8, 9 was covered 93% in survey area, and so this result reflect the stability of ecosystem. There was all the difference between the statement of environmental impact assessment of development concerned and this study result in the estimation of degree of green naturality. The plant community were divided into six groups in fifty-four plots by DCA and the dividing groups were P. densiflora, P. densiflora-Q. mongolica, P. densiflora-Q. serrata-F. mandschurica-B. davurica, Q. mongolica-Q. serrata-P. densiflora, Q. mongolica-Q. variabilis, Salix koreansis- B. davurica community. Except P. densiflora forest in survey site, the ecological succession trend of the other communities was seemed to be from P. densiflora to Q. spp.

• Journal of Korea Foundry Society
• /
• v.42 no.2
• /
• pp.83-93
• /
• 2022

Throughout this research course, we have analyzed the financial situation of more than 2,700 companies using credit evaluation disclosures from 2017 to 2019. The population was gathered based on the certification of Ppuri companies and Ppuri Expertise companies through the Korea National Ppuri Industry Center, accompanied by the NICE credit evaluation index. For the first time in Korea, we wanted to look at growth, profitability, and stability through financial analysis of the Ppuri industry. Through an indepth analysis, we identified operating income (rate), net income (rate), asset size, and debt ratio, along with three years of Ppuri company workers and total sales fluctuations, and looked at the financial structure per capita. In addition, financial status per person was compared by dividing Ppuri companies into six groups by employee size. Groups were 10 or fewer people, 11 to 20 people, 21 to 50 people, 51 to 200 people, 201-300 people, and 300 or more people; single individual companies were excluded for research convenience. Overall, the financial situation of Ppuri companies was judged to be in a very bad downturn, and financial indicators deteriorated over the course of the three years of investigation. In particular, the smaller the number of employees, the greater the financial fluctuations were and the worse the situations were. Among Ppuri companies, the casting industry, which is the technical starting point for the value chain of the industry, was found to also be in a very bad state, with continued workforce declines, total assets and sales reductions at severe levels, and operating income (rate) and net income (rate) also very poor. This is why we need a suitable and feasible policy direction, something that is difficult but must be allowed to develop.

• Current Research on Agriculture and Life Sciences
• /
• v.2
• /
• pp.56-62
• /
• 1984

This experiment was carried out to investigate the effects of distilled water, pH, uv-irradiation, carrier, emulsifier and organic solvent on the stability of butachlor formulations in the course of storage. The uv-irradiation increased the decomposition rate of butachlor formulations in the order of emulsifiable concentrate, sand coated granular and zeolite adsorbed granular. Decomposition of butachlor emulsion was not affected by water and pH. Decomposition of butachlor emulsifiable concentrate which were prepared with various organic solvents at $50^{\circ}C$ was higher in the polar organic solvents than in the non-polar organic solvent. Decomposition of butachlor-emulsifiable concentrate emulsified in Tween-60 was higher than in Hy-620C or Newkalgen-MC.

• Journal of Oriental Neuropsychiatry
• /
• v.13 no.1
• /
• pp.3-18
• /
• 2002

Hypertension excessively affects national health is the basic disease that causes death and disablement after the middle-aged. Therefore, The detection and control of hypertension is essential to health care. In general, It is known that the systolic blood pressure should be below 140mmHg, the diastolic blood pressure should be below 90mmHg. Presently, the treatment of hypertension is mostly taking anti-hypertension drug, diet and stability. but Taking anti-hypertension drug has such side effects as depression. and that, We were making a study of various treatments of hypertension. In a course of hypertension study, We applied aromatherapy to the control of hypertension. Aromatherapy is the practice of using of volate plant oils including essential oils, for psychological and physical well-being. Essential oils are drawn into the body by the sense smell not only does the aroma of the true plant stimulate the brain to the trigger a positive effect, but supply physical benefits also. In Europe and North America, The study and development of aromatherapy is lively in progress. In the control of hypertension, We applied Lavender, Majoram, Ylang-Ylang to forty-two hypertensive patients. After aromatherapy for controlling hypertension. We measured the changes of the systolic blood pressure & the diastolic blood pressure of patients by time. As the result of above study, We identified the significance of blood pressure down by aromatherapy.