• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.430-436
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• 2018

Special railway vehicles for track maintenance are equipped with a tamping device that adjusts various track trajectories to reduce the vibration of rolling stock and improve ride quality during trains passing over a track. The development of a simulator that can confirm the error of the actual tamping work is important for reducing human error in the linearization of the track misalignment. In this study, to improve the reality and training effect of conventional 2D simulator, 3D simulator modeling was implemented for tamping work of special railway vehicles in virtual space. The problem of buffering during high screen quality of tamping work was solved using the Unwrap UVW mapping technique of a low polygon extracted from high quality polygon modeling. The human error in the training of the tamping work was detected by the principle of circle and square collision when the tamping tyne and the sleeper collided. In addition, vibration of the driving chair was generated at the same time as the collision, and the number of the sleeper strikes is displayed on the simulator exercise screen. Owing to the scattering of railway ballast protruding from the sleepers, which had a serious effect on the safety of the vehicle, the gravel bouncing effect of the tamping unit was applied.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.157-162
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• 2003

The sludge oils were produced necessarily in the ships operation, so that it will be the best way to manage the sludge oils inside ship itself from a viewpoint of the prevention of marine oil pollution from ship. The ultrasonic breaking systems which recycle the sludge oil from ship into usable oil to be brunt is recognized as a most possible recycling device. In this regards, the purpose of this study is to examine erosion damage on the SS400 specimen by cavitation and the effect of impact pressure generated from the demolition of the cavity of ultrasonic vibration in the marine sludge oil environment .. The erosion damage of specimen was investigated mainly on weight loss, weight loss rate and maximum erosion rate with variation of the oil temperature as well as the change of space between transducer horn and specimen. The experimental results showed that as the space between ultrasonic vibrator horn and specimen disk increased, the weight loss and weight loss rate decreased and the values were larger in SFO than in SLO. The experimental results can be useful to the development of sludge oil disposing systems and to consider a countermeasure for the prevention of erosion damages by cavitation.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.192-198
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• 2015

Checked out by the moving vehicle health checks for patients, practitioners, and the increase in radiation dose outside the vehicle, but an investigation into the leakage of radiation can still be negligible. In this study, through experimental results were as follows: Dose that occurs most often where the leak in the right door $1.14{\pm}1.75mR/h$, X-ray generator in terms of proximity to the top $0.65{\pm}1.25mR/h$, X-ray generator and away to the bottom in terms $0.91{\pm}1.25mR/h$, the adjacent rear detector in the upper part $96.98{\pm}158.88mR/h$ dose of the leak appeared in various locations. By measuring position from the rear of the adjacent detector $67.48{\pm}97.03mR/h$ dose had the highest leakage into. Generating device for diagnosis of radiation safety regulations regarding the maximum leakage dose per week, but all met back when it is displayed in the leakage dose Hourly rates do not ignore the leakage radiation dose were measured. Therefore, a mobile health screening in a vehicle outside of the leakage radiation dose to the liver and move on we are not interested twelve barrier leakage radiation dose of defense has a chance to re-evaluate the standards required, and move the vehicle health check using the X-ray increases as the dose per hour, depending on the criteria for choosing the appropriate measures that will require effort.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.79-85
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• 2017

It is critical that passengers should be given timely and correct escape or evacuation guidance from captain and crews when there are hazardous situations in a ship. Otherwise the consequences could be disastrous as "SEWOL Ferry" the South Korean passenger ship which sank in southern coastal area on 16th April 2014. Due to the captain's delayed evacuation decision and lack of sufficient number of crews to guide passengers' evacuation, the accident recorded many casualties, most of whom were high school students (302 passengers sank down with the ship while 172 rescued). Building a passenger ship with well-designed physical escape routes is one thing and guiding passengers to those escape routes in real disaster situation is another. Passengers get panic and move to a wrong direction, bottleneck makes situation worse, and even crews get panic also - passive static escape route signage and small number of trained crews might not be enough to take care of them. SESS (Smart Escape Support System) is being developed sponsored by South Korea Ministry of Ocean and Fisheries starting from 2016 with 4 years of roadmap. SESS comprises multiple active dynamic signage devices which communicate with real-time escape routing server software via LoRa (Long Range) proprietary wireless network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.694-702
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• 2017

In the case of an elevated railway station, structure borne noise and vibration due to structural limitations allow the load and vibration from railway vehicles to be directly transmitted to the station structure, resulting in an increase in the number of civil complaints from customers and staff of the station. The floating slab track system, which is well known as one of the solutions for reducing the noise and vibration from elevated railway stations, usually contains rubber mounts or rubber pads under the railway slab which act as a damper. These types of device have the disadvantage that is difficult to predetermine the exact stiffness and damping ratio under the nonlinear loads resulting from train services. In this study, an isolator with a friction type of wedge is introduced, which can be applied to floating slab track systems and to be designed with precisely the required stiffness. Furthermore, a comparative analysis of the stiffness between the designed and experimental values is carried out, while the damping ratio, which is closely related to the friction wedge blocks, is deduced according to the train load condition. The performance tests of the isolator were conducted in accordance with the DIN 45673-7 standard which includes both static and dynamic load tests. The load conditions for the performance tests are designed to conform to the DIN standard related to the weight of the train and rail track, in order to perform vertical and horizontal load tests, so as to ensure the secure structural safety of the railway. Also, by checking the change aspect of the friction coefficients of the friction elements according to the loading rate, the vibration reduction performance of the friction type isolator with variable loading rate conditions is examined.

• Journal of Environmental Science International
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• v.17 no.9
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• pp.1005-1013
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• 2008

In this study, in order to analyze the air quality of the indoor environments of schools, we measured the indoor, outdoor and personal exposure concentration level of $PM_{10}$ for 40 classrooms(20 old, 20 new) in chungnam area from June 22 to July 19 and from November 21 to December 30, 2003. 1. Old classrooms contained more dust than new classrooms; the average of respirable dust is $43.27\;{\mu}g/m^3$ for new classrooms while $53.38\;{\mu}g/m^3$ for old one. The exposure concentration level of respirable dust in new classrooms were in summer higher outdoors than indoors. The values were indoors $46.71\;{\mu}g/m^3$, outdoors $50.46\;{\mu}g/m^3$, and personal $41.62\;{\mu}g/m^3$. Meanwhile in winter indoors had a higher concentration level than outdoors, the values being indoors $39.11\;{\mu}g/m^3$, outdoors $34.86\;{\mu}g/m^3$, and personal $49.01\;{\mu}g/m^3$. 2. Cr concentration level within dust was slightly higher in summer indoors ($101.50{\pm}32.10\;ng/m^3$) and outdoors ($100.89{\pm}35.18\;ng/m^3$) than winter indoors ($85.80{\pm}48.95\;ng/m^3$) and outdoors ($74.43{\pm}38.93\;ng/m^3$), but in personal concentration level, winter was higher. The results of this research show insufficient understanding of health risks from indoor air pollution, and shows possible health problems to students from school indoor air pollution. As such, a logical and systematic education program for students about the importance of indoor air quality should be carried out. Also the results of $PM_{10}$ concentration level measurements emphasize the need for regular measurements of indoor / outdoor and personal concentration level. New classrooms in particular needs to be used after measuring pollutants and safety, and requires installation of a ventilation device in all classrooms to improve air quality.

• Journal of Acupuncture Research
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• v.23 no.6
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• pp.239-254
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• 2006

The 3rd Japan-Korea Workshop on Acupuncture and EBM was held at Kanazawa on June $16^{th}$. From Korea team, 4 papers were presented. Dr. Hahn introduced a new approach of data analysis on series of n-of-1 trials using the Bayesian statistics. It offered important information for the future n-of-1 trials. Dr. Park clearly demonstrated the significance of various sham devices proposed and stressed the importance of research questions when we choose the control intervention in RCT. Dr. Lee reported the results of survey in Korean Medical Doctors (KMD) for their point selection and techniques to the distal and local points. Dr. Kim presented the results of face to face survey on the KMD with 28 items for acupuncture treatment on the knee OA. Finally, a draft of protocol was introduced by Dr. Kim. The title was "multi-center, a randomized, single blinded, two arms, parallel-group study to compare the effectiveness and safety of 'individualized acupuncture' and 'standardized minimal acupuncture' in Korean and Japanese patients with knee osteoarthritis (Phase IV)". From Japan team, 7 speakers presented their comments and proposals on the protocol. Dr. Takahashi introduced several issues regarding n-of-1 trials and pointed out the importance of obtaining generalizability from n-of-1 trials. Dr. Shichidou pointed the importance of research design, selection of outcome measures and reduction of biases. Dr. Itoh presented the results of point selection for the knee OA based on the literature survey. Dr. Sumiya introduced several differences between KMD and Japanese acupuncturists based on the questionnaire used in KMD survey. Dr. Furuya demonstrated a result of press tack needle and its sham device on shoulder stiffness. Dr. Yamashita introduced the results of literature survey regarding adverse events occurred by acupuncture on knee OA. Dr.Tsukayama stressed the importance of responsibility of Institutional Review Board (IRB) for the conduction of clinical trials. After several issues were discussed, the need of continued meeting for final protocol development was agreed, then the workshop was closed.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.43-52
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• 2018

The purpose of this study is to conduct a survey on awareness of the fourth industrial revolution being much debated recently and suggest the educational program for adult learner in order to create a new demand of university according to the social change. Based on earlier researches, the survey was conducted on employees working in the health and medical industry with questionnaire including the relevant educational field, areas of turnover and educational needs from July 1 to July 31, 2017. As a result, the bio-medical device, senior-friendly industry, environment and safety, clinical counselor and food service industry(coffee industry) were identified as necessary education areas. To enhance the validity of research results, in-depth interviews of relevant experts in each field were conducted from August 19 to September 22, 2017, and presented necessary education programs driven by the advent of the fourth industrial revolution and changes in each areas.

• Culinary science and hospitality research
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• v.22 no.8
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• pp.149-156
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• 2016

The purpose of this study is to reduce the contaminants (total volatile organic compounds (TVOCs), fine particle, odor and total airborne bacteria) during cooking process in cooking chamber, and to decrease the health damage in indoor space that has bad work environment. In order to solve the shortcomings of existing air purifiers and remove all kinds of pollutants effectively, this study focused on the development of indoor air purifiers which are made of bar type. Bio-ceramics filter which combines activated carbon and loess. The air cleaners developed with 4 measuring items including TVOCs, particulate matter, complex odor and total airborne bacteria were measured comparing their pre-service test to their post-service test after a period of time. The measured results showed higher removal efficiency of 91.02% as the concentration of TVOCs was reduced from $2,500{\mu}g/m^3$ to $223{\mu}g/m^3$. Second, the particulate matter removal ratio was 97.51% efficient with average concentration of $26.68{\mu}g/m^3$. Third, the odor showed 95.20% reduction as air dilution ratio averaged out at 144. Last, total airborne bacteria was eliminated by over 94% showing the changeable concentration from $787{\sim}814CFU/m^3$ to $47{\sim}40CFU/m^3$. In addition, the removal rate of harmful pollutants is excellent, and it is expected that the environment of the existing poor cooking room will be greatly improved by using the developed air purifier in combination with the ventilation device and the stove hood.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.171-181
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• 2003

The nose fairings of KSR-III are designed to be separated from the rocket by explosive force at the mission altitude to expose the payload. Adequate amount of separation force should be imposed to allow safe separation without collision between the fairings and the rocket, and the separation device was designed for the separation at very high altitude where almost no air load was expected. As the development of KSR-III goes on, several design changes have made and lower separation altitude of 45km is expected as a result. Under these circumstances, it is required to determine if the nose fairings can be separated without collision with much severer air load than for the design condition. In this study, the 6-DOF motion analysis program, PASEM, which was developed to predict the strap-on booster separation, is modified to simulate the pivotal motion of the fairings at early stages of separation. The accuracy of pivot motion simulation is validated by comparison with the results of ground test and the accurate separation conditions are deduced from it. Trajectory simulations are performed to see if separation without collision is possible with varying angle of attack, direction of gravity, and the effect of gust. It is also found that reducing the separation angle of the clamshell hinge from 60 degrees to 40 degrees can enhance separation safety and separation at lower altitude of 40km can be done without collision.