• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.251-257
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• 2017

Purpose: A chisel mounted on working implement, such as agricultural machinery used in irregular farming conditions, is subjected to highly variable fatigue loading during work. To ensure the safety of the chisel on a working implement for the duration of its service life, fatigue testing must be performed with the proper fatigue test load conditions. In this study, working loads for a chisel were developed by reconstructing loads from strain gage data collected during field tests and used to conduct fatigue tests on the chisel component. Methods: FE analysis with nCode software was utilized to select the proper quantity and locations of strain gages for load measurements. A fatigue test was performed to experimentally verify the fatigue strength of the chisel and to evaluate the validity of the load history developed with the load reconstruction technique. Results: A strain history for the chisel was obtained from data collected during field tests. The data was filtered for the 14-16 km/h speed range, connected, and merged. The chisel load history was developed using the load reconstruction technique. The resulting load history was expressed as a load spectrum using the rain-flow counting method. Conclusions: A fatigue test was conducted on a chisel under a constant load condition with an equivalent load amplitude and number of cycles, as calculated by Miner's Rule for linear damage accumulation. During the fatigue test, there were no cracks at any position. It is concluded that the fatigue test method proposed in this study can be utilized successfully as a durability evaluation method for the chisel.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.489-495
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• 2018

The purpose of this study was to investigate the effect of fouls on performance in field hockey games. A total of 33 matches and 2101 fouls from 10 teams participated in the 2017 World League SEMI-FINAL tournament were analysed by region, race, type, and cause. The total data that is analysed by SportsCode and SPSS(correlation analysis & chi-square test)have showed that the top ranked countries had a higher foul frequency than the lower ranked nations. According to the situation that has showed the result of the analysis, it showed that there was no difference between the results analysed on the foul type and the attacking and defence situation but it has indicated that area, game situation and the cause of fouls showed there was a significant difference. On these results, it is hoped to use fouls as one of the tactical means in women's field hockey games.

• Nuclear Engineering and Technology
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• v.52 no.4
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• pp.742-754
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• 2020

Zircaloy cladding oxidation is an important phenomenon for both design basis accident and severe accidents, because it results in cladding embrittlement and rapid fuel temperature escalation. For this reason during the last decade, many experts have been conducting experiments to identify the oxidation phenomena that occur under design basis accidents and to develop mathematical analysis models. However, since the study of design extension conditions (DEC) is relatively insufficient, it is essential to develop and validate a physical and mathematical model simulating the oxidation of the cladding material at high temperatures. In this study, the QUENCH-05 and -06 experiments were utilized to develop the best-fitted oxidation model and to validate the SPACE code modified with it under the design extension condition. It is found out that the cladding temperature and oxidation thickness predicted by the Cathcart-Pawel oxidation model at low temperature (T < 1853 K) and Urbanic-Heidrick at high temperature (T > 1853 K) were in excellent agreement with the data of the QUENCH experiments. For 'LOCA without SI' (Safety Injection) accidents, which should be considered in design extension conditions, it has been performed the evaluation of the operator action time to prevent core melting for the APR1400 plant using the modified SPACE. For the 'LBLOCA without SI' and 'SBLOCA without SI' accidents, it has been performed that sensitivity analysis for the operator action time in terms of the number of SIT (Safety Injection Tank), the recovery number of the SIP (Safety Injection Pump), and the break sizes for the SBLOCA. Also, with the extended acceptance criteria, it has been evaluated the available operator action time margin and the power margin. It is confirmed that the power can be enabled to uprate about 12% through best-estimate calculations.

• Journal of Radiation Protection and Research
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• v.12 no.1
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• pp.34-39
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• 1987

Radiation shielding analysis for a 6MeV X-ray facility was carried out. The primary and leakage radiation for the facility can be evaluated based on the methodology in NCRP No. 49 and 51. The present study deals with radiation scattering analysis for the outside and inside door of the facility based on the albedo concept. The calculated dose rates were compared with the results of MORSE-CG code calculation and the measured data, resulting in a good agreement, even though there existed some deviation for the inside door. These results can be utilized to the radiation shielding design of the medical and industrial X and gamma ray facilities, and to the safety evaluation of these facilities.

• The Journal of Internal Korean Medicine
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• v.33 no.4
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• pp.485-497
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• 2012

Objectives : The aim of this study was to systematically investigate herbal-drug-associated adverse drug reactions (herbal ADRs) reports submitted by a single oriental hospital and to analyze the general characteristics, causative agents, clinical manifestations, severity and types of herbal medicines which caused herbal ADRs. Methods : This study proceeded with IRB approval. The data on herbal ADR were collected prospectively from January 2008 to February 2012 by EMR of Dongguk University Ilsan Oriental Hospital. The World Health Organization (WHO)-Uppsala Monitoring Center (UMC) criteria was used to determinate causality for each herbal ADR. WHO-Adverse Reaction Terminology (WHO-ART) System Organ Class (SOC) code and WHO severity category were also used in this study. Results : A total of twenty eight cases were reported. Twenty two cases were assessed to have over possible relations with herbal medication. The gender ratio of these cases were 64.6 percent female and 36.4 percent male, demonstrating no statistical significance. Patients aged over 60 were 59.1%. Gastro-intestinal system was reported to be the most frequently affected organ (38.8%), and followed by psychiatric system (22.4%), and integumentary system (22.4%). The most common clinical symptom was headache (12.2%), followed by diarrhea (10.2%), and pruritus (10.2%). The severity of most cases was assessed to be mild (89.8%). The percentage of moderate ones was 10.2%, and there were no severe cases. Conclusions : Progressive study and further analysis on herbal ADRs are warranted for safety in the clinical use of herbal medicines.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1170-1179
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• 2009

The purpose of this work is to predict the low frequency aero-acoustic noise generated from the horizontal axis wind turbine, NREL Phase VI for the whole operating conditions of various wind speeds using large eddy simulation and Ffowcs-Williams and Hawkings model provided in the commercial code, FLUENT. Because there is no experimental data about wind turbine noise, we first of all compared aerodynamic performance such as shaft torque and power with experimentally measured value. Performance results show a good agreement with experimental data within about 0.8%. As the wind speed increases, the overall sound pressure level and the sound pressure level by the quadrupole and dipole source show a increasing tendency. Also, sound pressure level is proportional to $r^{-2}$ in the near field and $r^{-1}$ in the far field according to the increase of distance from the center of hub of wind turbine. According to 2 times increase of distance, sound pressure level is reduced by about 6dB.

• Health Policy and Management
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• v.23 no.3
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• pp.260-265
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• 2013

Background: The aim of this study was to examine the seasonal variation of death from intentional self-harm by hanging, strangulation and suffocation (HSS: Korean Standard Classification of Diseases-6 code: X70) using the 2011 death registry data. Methods: The analysis was based on data of 8,359 HSS deaths from 2011 national vital statistics in Korea. Daily, weekly, and monthly death pattern on HSS were used to examine the relationship seasonal variation and HSS deaths. Results: A total of 8,359 HSS deaths occurred in 2011, with a mean age of 50.6 years. The HSS death rate (per 100,000) was 25.5 in male and 10.8 in female. In one day 17.6 males and 8.0 females occurred HSS death on average. The number of HSS death per day was the highest on 8th June (45 deaths), and lowest on 1st February (7 deaths) during the period. The variations of daily HSS death showed wide fluctuation from a peak of 34 to 45 deaths (29th May to 9th June) to a trough of 17-26 deaths (10th-13th September: the Korean thank-giving consecutive holidays), 13-20 deaths (2nd-5th February: the new year's day by the lunar calendar) and 8-9 deaths (24th-25th December: Christmas holidays). There were no significant difference between gender and seasonal variation (month, season, and week). Conclusion: The mean number of HSS death per day was highest in June (30.6 deaths), and months with the lowest number of deaths was January and December (range, 19.4 to 19.6 deaths). HSS death were more prevalent during summer and spring and were less likely to occur during winter. On Saturdays (21.0 deaths), the number of HSS death per day was the lowest, and Monday (27.9 deaths) was the highest. HSS death was less likely to occur on holidays (21.4 deaths). There was significant seasonal variation in HSS death by weekly and monthly (p<0.01).

• Journal of Preventive Medicine and Public Health
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• v.40 no.4
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• pp.329-335
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• 2007

Objectives : To identify the effects of supplemental private health insurance on health care utilization and expenditure under the mandatory National Health Insurance(NHI) system in Korea. Methods : The data were collected by the National Cancer Center in Korea. Cancer patients who were newly diagnosed with stomach (ICD code, C16), lung(C33-C34), liver (C22), colorectal cancer(C18-C20) or breast(C50) cancer were included as study subjects. Data were gathered using a structured questionnaire from face-to-face interviews, the hospital Order Communication System (OCS) and medical records. Clinical, socio-demographic and private health insurance related factors were also gathered. The differences of health care utilization and expenditure were compared between those who have private health insurance and those who do not using t-test and multivariable regression analysis. Results : Individuals with private health insurance spent larger inpatient costs than those without, but no differences were found in utilization in other service such as hospital admissions, hospital days and physician visits. Conclusions : We found that private health insurance exerts a significant effect on the health care expenditure in inpatient service. These study results can provide a rational basis to plan a national health policy regarding private health insurance. Further studies are needed to investigate the impacts of private health insurance on cancer patients' outcomes and survival rates.

• Journal of Advanced Navigation Technology
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• v.6 no.1
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• pp.44-51
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• 2002

This paper describes the performance evaluation and analysis of an Orthogonal Frequency-Division Multiplexing (OFDM) system having the least Inter Symbol Interference (ISI) in a multi-path fading channel environment. Wireless Local Area Network (W-LAN) in accordance with IEEE 802.11a and IEEE 802.11b provides high-speed transmission to universities, businesses and other various places. In addition, service providers can offer a public W-LAN service on restricted areas such as a subway. The proliferation of W-LAN has led to greater W-LAN service demands, but problems are also on the rise in offering a good W-LAN service. In particular, urban areas with high radio wave interference and many buildings are vulnerable to deteriorated QoS including disconnected data and errors. For example, when high-speed data is transmitted in such areas, the relatively high frequency generates ISI between Access Points (AP) and Mobile Terminals (such as a notebook computer), leading to a frequency selective fading channel environment. Consequently, it is difficult to expect a goodW-LAN service. The simulation proves that the OFDM system enables W-LAN to implement QoS in high-speed data transmission in a multi-path fading channel environment. The enhanced OFDM performance with 52 sub-carriers is verified via data modulation methods such as BPSK, QPSK and 16QAM based on IEEE 802.11a and punched convolutional codes with code rate of 1/2 and 3/4 and constraint length of 7. Especially, the simulation finds that the OFDM system has better performance and there is no data disconnection even in a mobile environment by applying a single tap equalizer and a decision feedback equalizer to a mobile channel environment with heavy fading influence. Given the above result, the OFDM system is an ideal solution to guarantee QoS of the W-LAN service in a high-speed mobile environment.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.6
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• pp.93-103
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• 2018

In the past, the rooftop was a place where a water tank was to be installed, and a space of secretion and concealment such as a warehouse exposed in the air. It was because it was judged to hinder the beauty of a city as a whole without having any functional value per se. However, the roof portion is increasingly being utilized for a space such as a cafe, a pub, and a lounge as the rooftop is highly recognized as a place for leisure activities other than an idle space in modern times. Nonetheless, there are no detailed ordinances and criteria corresponding to such circumstances. For example, in case of the rooftop space, the building code applied to the rooftop space is a legal system when the rooftop was an idle space in the past though people have now accessed more increasingly to the rooftop than in the past. This study investigated the definition on the rooftop space evolved in accordance with the change of the rooftop space and the related legal system in Korea, and conducted a survey for the purpose of performing the field investigation for the analysis of physical status in 117 spaces that form the rooftop space in the rooftop of small-scale commercial facilities with 2 stories through 4 stories in Korea and analyze the recognition of users and analyzing the recognition of users. We analyzed the problems in the rooftop space through analysis of derived data, and suggested improvement plans.