• Radiation Oncology Journal
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• v.17 no.2
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• pp.172-178
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• 1999

Purpose : To measure the basic structural characteristics of radiation oncology facilities in Korea during 1997 and to compare personnel, equipments and patient loads between Korea and developed countries. Methods and Materials : Mail serveys we conducted in 1998 and data on treatment machines, personnel and peformed new patients were collected. Responses were obtained from the 100 percent of facilities. The consensus data of the whole country were summarized using Microsoft Excel program. Results: In Korea during 1997, 42 facilities delivered megavoltage radiation theraphy with 71 treatment machines, 100 radiation oncologists, 26 medical physicist, 205 technologists and 19,773 new patients. Eighty nine percent of facilities in Korea had linear accelators at least 6 MeV maximum photon energy. Ninety five percent of facilities had simulators while five percent of facilities had no simulator, Ninety one percent of facilities had computer planning systems and eighty three percent of facilities reported that they had a written quality assurance program. Thirty six percent of facilities had only one radiation oncologist and thirty eight percent of facilities had no medical physicists. The median of the distribution of annual patients load of a facility, patients load per a machine, patients load per a radiation oncologist, patients load per a therapist and therapists per a machine in Korea were 348 patients per a year, 263 patients per a machine, 171 patients per a radiation oncologist, 81 patients per a therapist, and 3 therapists per a machine respectively. Conclusions : The whole scale of the radiation oncology departments in Korea was smaller than Japan and USA in population ratio regard. In case of hardware level like linear accelerators, simulators and computer planning systems, there was no big differences between Korea and USA. The patients loads of radiation oncologists and therapists had no significant differences as compared with USA. However, it was desirable to consider the part time system in USA because there were a lot of hospitals which did not employ medical physicists.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.135-143
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• 2008

An emergy concept was used to evaluate the environment and economy of the estuarine areas of Yeongsan River, Seomjin River, and Han River in Korea. The emergy evaluations clearly showed ecological and socioeconomic characteristics of the estuarine areas that act as ecological and economic centers of surrounding areas. River, tide, and rain provided most of the renewable emergy inputs to the estuarine areas with their contribution to the total emergy input less than 8%. The estuarine areas mostly relied for their operation on the purchased emergy which accounted for $92{\sim}98%$ of the total emergy input to the systems. Emergy indices such as emergy use per unit area, population carrying capacity, environmental loading ratio, and emergy sustainability index revealed that the estuarine areas of Yeongsan River, Seomjin River, and Han River are not sustainable at the current level of economic activities in the areas. The ecological economic values of the environment of the areas were in the range of $7.29{\sim}22.06$ million Em\/ha/yr. They are more than twice that for the whole country, indicating the ecological and economic importance of the eatuarine areas. It is, therefore, urgent to establish and implement estuarine management policies to protect and restore the ecological and economic potentials of the estuarine areas of Yeongsan River, Seomjin River, and Han River. Management plans for the estuarine areas should include both demand-side measures such as reduction of population and economic concentration and consideration of ecological carrying capacity in planning stages for utilization and development of the areas, and supply-side ones such as restoration of degraded ecosystems and construction of new productive ecosystems.

• Korean Journal of Agricultural Science
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• v.20 no.1
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• pp.68-87
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• 1993

Data acquisition system and computer program developed in this study could be well used in engine vibration analysis. The system and program developed were also operated to be able to control measuring interval, number of channels, number of data. The flywheel was specially studied to provide the proper weight with rubber damper for the engine design at low level of vibration. This study was conducted to obtain basic data which affect the engine vibration. The experiment of this study was performed on original weight flywheel, weight-reduced flywheel, weight-reduced and rubber-coated flywheel, weight-reduced and damper-attached flywheel. Avarage of peak value, maximum vibration, power spectrum density based on FFT analysis are major factors of this experiment. Results were obtained as follows : 1. When rubber was inserted in the flywheel rim of which weight was reduced from 32.2kgf to 24.4kgf, maximum vibration of the engine was decreased 48.3% at X axis, 35.5% at Y axis and 34.6% at Z axis in comparison with the flywheel of original weight. 2. When the flywheel of rubber damper was compared with the original flywheel, the average of absolute vibration for rubber damped flywheel was decreased at X, Y, Z axis and especially its decreasing rate was so high at X-axis comparing with the other flywheel, which implied that rubber damper was very useful to reducing the vibration of the engine at X axis. 3. Hysteresis losses of X, Y, Z axis were greatly decreased in the flywheel with rubber damper on rim. 4. Damped oscillation effect on X and Y axis vibration above average peak vibration by the flywheel of rubber damper on rim was larger than those by the other flywheels. 5. Power spectrums of vibration at real and imaginery part were bi-mode type. The vibration frequency of rubber dampered flywheel which weight is decreased was slightly increased as compared with original flywheel.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1213-1221
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• 2006

In this study, granular sludge used in an anaerobic process treating brewery waste was inoculated in a laboratory scale of reactor to induce anaerobic ammonium oxidation(ANAMMOX). The reactor was operated with synthetic wastewater, which prepared at 1:1 ratio of $NH_4^+-N$ over $NO_2^--N$. Changes in nitrogen concentration, COD, alkalinity and gas production were analyzed. There are 3 phases of spanning in experimental period according to influent nitrogen concentration. In the Phase 1, each of the concentration of $NH_4^+-N$ and $NO_2^--N$ were increased from 1.91 $gN/m^3{\cdot}d$ to 14.29 $gN/m^3{\cdot}d$. Ammonium nitrogen loading(same as nitrite nitrogen) was 23.81 $gN/m^3{\cdot}d$ in the Phase 2 and 19.05 $gN/m^3{\cdot}d$ in the Phase 3, respectively $NO_2^--N$ has been removed up to 99% during whole period while the removal efficiency of $NH_4^+-N$ was significantly varied. In Phase 2, $NH_4^+-N$ was removed up to 75%. Microorganisms varied temporally through three phases were characterized by 16s rDNA analysis methods. ANAMMOX bacteria were dominantly found in phase 2 when the removal rate of $NO_2^--N$and $NH_4^+-N$ was the highest up to 99% and 75%, respectively. Due to erroneous exposed to air, the removal efficiency of $NH_4^+-N$ was unexpectedly lowered, but ANAMMOX bacteria still existed.

• FLOWER RESEARCH JOURNAL
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• v.18 no.3
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• pp.186-192
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• 2010

An infrared heating system, installed in a small venlo-type glasshouse ($280m^2$) in Gyeongsang National University, Jinju, Korea, was used to investigate its heating effect with potted Phalaenopsis, Schefflera arboricola 'Hongkong', Ficus elastica 'Variegata', and Rosa hybrida 'Yellow King' as the test plants. Temperature changes in test plants with the system turned 'On' and 'Off' were measured by using an infrared camera and the consumption of electricity by this infrared heating system was measured and analyzed. In potted Phalaenopsis, when the set air temperature of the greenhouse was $18^{\circ}C$, temperature of leaves and the growing medium were $22.8{\sim}27^{\circ}C$ and $21.3{\sim}24.3^{\circ}C$, respectively. In such tall plants as Schefflera arboricola 'Hongkong' and Ficus elastica 'Variegata', the upper part showed the highest temperature of 24.0 and $26.9^{\circ}C$, respectively. From the results of temperature change measurements, the plant temperatures were near or above the set point temperatures with some fluctuations depending on the position or distance from the infrared heating system. When air temperature between night and dawn dropped sharply, plant temperatures were maintained close to the set temperature ($18^{\circ}C$). There was a significant difference between 'On' and 'Off' states of the infrared heating system in average temperatures of root zone and leaf: 21.8 and $17.8^{\circ}C$ with the system 'On' and 20.4 and $15.5^{\circ}C$ with the system 'Off', respectively, in a cut rose Rosa hybrida 'Yellow King'. The heating load was about $24,850{\sim}35,830kcal{\cdot}h^{-1}$, which comes to about 27,000~40,000 won in Korean currency when calculated in terms of the cost of heating by a hot water heating system heated by petroleum. The cost for heating by the infrared heating system was about 35% of that of a hot water heating system. With the infrared heating system, the air temperature during the night was maintained slightly lower than the set point air temperature, probably due to the lack of air tightness of the glasshouse. Therefore, glasshouses with an infrared heating system requires further investigation including the installation space of the heat-emitting units, temperature sensor positions, and convection.