• Journal of the Korea Institute of Building Construction
• /
• v.15 no.6
• /
• pp.653-660
• /
• 2015

Technologies for reducing construction duration are key factors in nuclear power plant construction projects, as a reduction in construction duration at the construction phase leads to a reduction in construction cost and an increase in profits through the early operation of the nuclear power plant. To analyze the constructability of the height of single-layer placement of formwork for the Reactor Containment Building (RCB) exterior wall through lateral pressure according to the height of concrete placement, the deformation criteria for formwork, and a new form design, 'MIDAS GEN (hereinafter referred to as MIDAS)' is used in this study. The cost and workload of formwork are derived according to the unit of height of the RCB exterior wall. Based on the result, it was found that the higher the RCB exterior wall, the higher the material cost, and the less the construction duration and the less the total number of formwork layers. Based on this result, it is believed that the material cost and the construction duration can be appropriately determined according to the formwork height.

• Journal of muscle and joint health
• /
• v.5 no.2
• /
• pp.222-237
• /
• 1998

In an attempt to investigate the effect of long-term aquatic exercise program on lower limbs' muscle strength, knee Joint flexion, pain reduction and weight changes with aquatic exercise program. Forty three women with arthritis were pre and post tested for changes of muscle strength, range of motion, weight and pain. This data was collected from April 1, 1997 to February 24, 1998. The mean age was 52.5. Statistically significant in lower limbs' muscle strength with an aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 12 weeks after experiment. Statistically significant in knee joint flexion with aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 12 weeks after experiment. Statistically significant in pain reduction with aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 12 weeks after experiment. Statistically significant in weight changes with aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 6 weeks after experiment. As a conclusion, aquatic exercise programs for the patients with arthritis require at least 12 weeks and a variety of aquatic exercise programs for the effective control should be developed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.258-261
• /
• 2006

This study introduces the control of duration time of impulse noises emitted from a high voltage COS fuse of a transformer. When a high voltage COS fuse becomes a short circuit by the over current, the peak sound pressure level over 150 dB(A) is generated at the distance of 2m from a COS Fuse. For the purpose of the reduction of impulse noise, in this study, the reactive type silencer has been utilized. And also electrical interrupting test was experimented. From the experimental results, the reactive type silencer has been shown to have the noise reduction of about 13 dB(A). It has been found that the electrical interception performance of the COS fuse was related to the control of the duration time of impulse noise.

• Journal of ILASS-Korea
• /
• v.21 no.1
• /
• pp.20-28
• /
• 2016

This paper presents an experimental study on the GDI injector with Bosch method. The injection characteristics, such as the injection quantity, the injection rate, the maximum velocity of the nozzle exit and the injection delay were studied through the change of the injection pressure, the tube pressure and energizing duration in injection rate measurement device using nheptane. The injection quantity is increased by increasing injection pressure, decreasing tube pressure or increasing energizing duration. As the difference of the injection quantity changed, the shape of injection rate was moved with a constant form. The maximum velocity of the nozzle exit showed a tendency to increase as the injection pressure is increased. However, tube pressure did not affect. Overall, it was confirmed that the closing delay is longer than the opening delay in all conditions. As the injection pressure increased, the result has a tendency to decrease the closing delay, it did not affect the opening delay. Reduction of the closing delay showed the reduction of the injection duration. the tube pressure and energizing duration did not affect the injection delay (opening delay, closing delay).

• Structural Engineering and Mechanics
• /
• v.54 no.5
• /
• pp.937-953
• /
• 2015

This paper investigates the load model for single footfall trace of human walking. A large amount of single person walking load tests were conducted using the three-dimensional gait analysis system. Based on the experimental data, Fourier series functions were adopted to model single footfall trace in three directions, i.e. along walking direction, direction perpendicular to the walking path and vertical direction. Function parameters such as trace duration time, number of Fourier series orders, dynamic load factors (DLFs) and phase angles were determined from the experimental records. Stochastic models were then suggested by treating walking rates, duration time and DLFs as independent random variables, whose probability density functions were obtained from experimental data. Simulation procedures using the stochastic models are presented with examples. The simulated single footfall traces are similar to the experimental records.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.32 no.3
• /
• pp.234-240
• /
• 2019

In this work, the magnetic arc reduction phenomena encountered in AC relay contacts were analyzed. To this end, arc duration, instantaneous voltage, and current changes due to changes in the magnetic field were observed. The arc generated at the contact point was affected by the magnitude of the applied magnetic field; the voltage and current waveforms rapidly intersected, resulting in a decrease in arc duration and arc energy. Furthermore, the orientation of the N pole of the magnetic field was found to play a role in the effectiveness of potential arc prevention.

• Journal of Biosystems Engineering
• /
• v.4 no.1
• /
• pp.76-86
• /
• 1979

This study was conducted to find out the effects of rainfall occurring during the paddy sun-during process of traditional paddy harvesting operations on the quality of milld rice. Rice varieties used for the experiment were MINEHIJARI variety a japonica and SUWEON 264 vareity , a sister-line of TONG-IL . Sun-drying days after the paddy cutting, times of storm occurrance during sun-drying period, and storm duration were treated as variables. The results is summarised as follows : 1. Brown rice recovery exposed to rainfall during the sun-druing period were ranged 81.6-82.1% and 79.4-80.2% for MINEHIKARI and SUWEON 264 varieties, respectively. which showed negligible effect by rainfall. 2. Milling recovery of MINEHIKARI variety was not affected by storm duration but by the by the sun-drying days after cutting as the sun-drying days increased to eight and four days when the variety met the rainfall one and two times, respectively. The range of milling recoveries of MINEHIKARI variety were 75.18-74.07% and 75.24-73.46% as the variety met the rainfall one and two times, respectively, and it were estimated that up to 0.9% and 1.5% of milling recovery would be reduced by one and two times of rainfall during sun-drying period. 3. The milling recovery of SUWEON 264 variety was affected only by the increase of drying days after cutting when it met one time of rainfall during the sun-drying period, while it was begun to reduce by the storm duration more than 11hours as the drying paddy met two times of rainfall. The milling reveries of the paddy met one and two times of rainfall were ranged 74.24-73.21% and 74.02-72.36% which were estimated to be reduced up to 0.9 % and 1.8% by the increase of the drying days after cutting and storm duration , respectively. 4. The head rice recovery of MINEHIKARI rice variety showed notable decrease as the drying days after cutting increased, and also it was greatly reduced even by the five hours of storm duration when one time of rainfall occurred but it was not affected by storm duration when the rainfall occurred two times. Head rice recoveries of MINEHIKARI met one and two times of rainfall during the sun-drying period were 65. 15 -40.85% and 61.86 - 30.03 %, which showed terrible reduction as much as up to 25% and 35% compared to that which did not met rainfall during the sun-drying process. 5. Head rice recovery or SUWEON 264 variety was very much reduced as the sum-drying days after cutting increased. Storm duration less than five hours during the sun-drying process did not affect on the decrease of head rice recovery when the variety was exposed to one time of rainfall, while storm duration affected considerably on the reduction of head rice recovery of SUWEON 264 variety exposed to two times of rainfall. The range of head rice recovery, 56.43 - 33.94% and 51.28 - 21.03% , for the paddy exposed to rainfall one and two times were evaluated that up to 24% and 37% of reduction in head rice recovery would be brought about compared to the head rice recovery of the sundriedpaddy that did not met the rainfall.

• Journal of Biosystems Engineering
• /
• v.4 no.1
• /
• pp.75-75
• /
• 1979

This study was conducted to find out the effects of rainfall occurring during the paddy sun-during process of traditional paddy harvesting operations on the quality of milld rice. Rice varieties used for the experiment were MINEHIJARI variety a japonica and SUWEON 264 vareity , a sister-line of TONG-IL . Sun-drying days after the paddy cutting, times of storm occurrance during sun-drying period, and storm duration were treated as variables. The results is summarised as follows : 1. Brown rice recovery exposed to rainfall during the sun-druing period were ranged 81.6-82.1% and 79.4-80.2% for MINEHIKARI and SUWEON 264 varieties, respectively. which showed negligible effect by rainfall. 2. Milling recovery of MINEHIKARI variety was not affected by storm duration but by the by the sun-drying days after cutting as the sun-drying days increased to eight and four days when the variety met the rainfall one and two times, respectively. The range of milling recoveries of MINEHIKARI variety were 75.18-74.07% and 75.24-73.46% as the variety met the rainfall one and two times, respectively, and it were estimated that up to 0.9% and 1.5% of milling recovery would be reduced by one and two times of rainfall during sun-drying period. 3. The milling recovery of SUWEON 264 variety was affected only by the increase of drying days after cutting when it met one time of rainfall during the sun-drying period, while it was begun to reduce by the storm duration more than 11hours as the drying paddy met two times of rainfall. The milling reveries of the paddy met one and two times of rainfall were ranged 74.24-73.21% and 74.02-72.36% which were estimated to be reduced up to 0.9 % and 1.8% by the increase of the drying days after cutting and storm duration , respectively. 4. The head rice recovery of MINEHIKARI rice variety showed notable decrease as the drying days after cutting increased, and also it was greatly reduced even by the five hours of storm duration when one time of rainfall occurred but it was not affected by storm duration when the rainfall occurred two times. Head rice recoveries of MINEHIKARI met one and two times of rainfall during the sun-drying period were 65. 15 -40.85% and 61.86 - 30.03 %, which showed terrible reduction as much as up to 25% and 35% compared to that which did not met rainfall during the sun-drying process. 5. Head rice recovery or SUWEON 264 variety was very much reduced as the sum-drying days after cutting increased. Storm duration less than five hours during the sun-drying process did not affect on the decrease of head rice recovery when the variety was exposed to one time of rainfall, while storm duration affected considerably on the reduction of head rice recovery of SUWEON 264 variety exposed to two times of rainfall. The range of head rice recovery, 56.43 - 33.94% and 51.28 - 21.03% , for the paddy exposed to rainfall one and two times were evaluated that up to 24% and 37% of reduction in head rice recovery would be brought about compared to the head rice recovery of the sundriedpaddy that did not met the rainfall.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.24 no.3
• /
• pp.41-57
• /
• 2021

This study evaluated the application of water quality management measures using the SWAT model and the effectiveness of the measures using the load duration curve targeting the Seohwacheon watershed located upstream of Daecheongho. As water quality management measures, artificial wetlands, reduction of neglected livestock, reduction of runoff from greenhouses, restoration of ecological rivers, application of LID technology, and management of point sources were applied. The applied technology evaluated the efficiency of water quality improvement measures by using the target water quality excess rate and the degree of load reduction for each sulfur through the load duration curve. The load duration curve was created by creating a long-term flow duration curve using SWAT and multiplying it by the target water quality. For the target water quality, the value corresponding to the 60th percentile was set as the target water quality using the 10-year data from the Okcheoncheon water quality observation point located in the downstream of Seohwacheon. Through this study, it was possible to confirm the applicability of various water quality measures through the SWAT model, and to examine the applicability of each period according to the sulfur through the load retention curve.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.29 no.6
• /
• pp.392-396
• /
• 2003

Purpose : The purpose of this study was to find the predictors for successful arthrocentesis for anterior disc displacement without reduction(ADD without Reduction) of the temporomandibular joint (TMJ). Patients and Methods : Arthrocentesis and lavage was carried out in 25TMJs of 22patients whose MRI findings were all anterior disc displacement without reduction. The effectiveness of the treatment was evaluated in terms of the postoperative range of maximal mouth opening (MMO) and the degree of postoperative pain score. Predectors which was analyzed were age, duration of painful locking, MMO, the degree of pain, perioperative clicking and the amounts of irrigation fluid. Results: 18cases (72%) was included to criteria for success. There were no significant differences in age, duration of locking, MMO and the degree of pain statistically. But In 15cases(83%) of successful cases, amouts of irrigated solution recovered to normal MMO were less than 150ml. And In 8cases (44%) of successful cases, perioperative clicking was appeared. Conclusion : Amounts of irrigated solution recovered to normal MMO and the appeareance of perioperative clkicking may be predictors of the successful results of arthrocenetesis of ADD without reduction of TMJ.