• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.1
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• pp.1-7
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• 2024

Weather is one of the main causes of aircraft accidents, and among the phenomena caused by weather, icing is a phenomenon in which an ice layer is formed when an object exposed to an atmosphere below a freezing temperature collides with supercooled water droplets. If this phenomenon occurs in the rotor blades, it causes defects such as severe vibration in the airframe and eventually leads to loss of control and an accident. Therefore, it is necessary to foresee the icing situation so that it can ascend and descend at an altitude without a freezing point. In this study, vibration data in normal and faulty conditions was acquired, data features were extracted, and vibration was predicted through deep learning-based algorithms such as CNN, LSTM, CNN-LSTM, Transformer, and TCN, and performance was compared to evaluate blade icing. A method for minimizing operating loss is suggested.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.1
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• pp.187-192
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• 2015

In general, design of urban intersections are fundamentally different from rural intersections, but current urban intersection design has been appled to rural standards. This study has suggested the design standard for urban intersection grades based on the existing literature, field investigating and comparative analysis. Moreover, this study analyzes and compares the differences between urban and rural intersections, and intersections have been derived by appropriate design standards after reviewing the domestic and international grades design criteria. Site survey was performed to validate the derived design criteria by analyzing statistically to establish the design standards. Results were produced for the intersection portion grade standards by comparing the number of instructions which produced appropriate slope degree from 2.5% to 3% in normal condition and slope can be extended to 5% in some critical cases. In-situ investigation was performed to validate the produced data where slope was found from 0.0~8.6%. Additional data of accident analysis were also collected for the validation of the suggested data and correlation analysis was performed using the SPSS tool. Data were analyzed statistically using 95% significance level for vehicle-to-vehicle collided, head-on collision accident rates, where accident rates significantly correlated with the grade. Therefore, appropriate grade at the intersection should be designed and applied in order to reduce the number of accidents at the intersection. Finally, appropriate grades for urban intersections are suggested from 1-3% for normal cases and grades could extend up to 5% for unavoidable cases where extra care must be taken when designing.

• Child Health Nursing Research
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• v.19 no.4
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• pp.282-290
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• 2013

Purpose: The purpose of this study was to analyze life respect-related content in the 7th to 10th grade textbooks of middle and high schools. Methods: Sixty two textbooks adopted as middle and high school textbooks were analyzed for content on life respect. Results: There were 6 categories related to life respect content in the 7th to 9th grade textbooks ("prevention of accidents and the first-aid", "mental health", "sex and health", "prevention of drug abuse, smoking and drinking", "normal life and health", and "society and health"). Content on life respect in the 10th grade textbooks was categorized as "drug abuse, smoking, drinking, and health", "sex and health", "mental health", "life science and treating human life too lightly", "normal life and health", and "society and health". Conclusion: Content on life respect attached importance to more practical issue such as prevention of violence and suicide rather than fundamental understanding about self and life. These results suggest that the content on life respect should help adolescents find their own values and meaning of life within the concept of coexistence.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.55-61
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• 2012

Road signs are important facilities in terms of providing information to driver, they are helpful for driver's judgment as deliver it's own information. However if there is occurrence dew on the road sign because of the change of temperature and humidity, it can be cause of accidents. Therefore it is necessary to develop anti-dew or dew resistance technology. In this research the anti-dew technologies such as insulation road sign and anti-dew film were compared with normal road sign, and the effectiveness analysis was conducted for each alternatives. The quantity of dew on the road sign was check using ANOVA and Tukey HSD and the relation between the retro-reflectivity and quantity of dew on the sign was check using Pearson correlation coefficient. As a result, the sample of anti-dew film attached road sign showed lesser quantity of dew compared with normal road sign. After 90 seconds, the difference of dew quantity for anti-dew film and insulation road sign showed statistically significant result. The relation of between quantity of dew and retro-reflectivity was inverse correlation. As a result, when analyzed the quantity of dew and retro-reflectivity a point of view anti-dew effectiveness, the anti-dew film and insulation road sign showed meaningful result.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1976.06a
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• pp.86.2-86
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• 1976

Authors have performed the audiological analysis in accordance with age, sex, site, duration, cause, ear drums, curve pattern, and hearing level taken from 165 patients (Male; 101, Female; 64) with non-perforated ear drums who had complained hearing impairment. The results are as follows. 1. The audiographic pattern has classified into Normal (30 cases, 18.18%), Flat form (46 cases, 20.6%), Ascending form (5 cases, 3%), Mountain form (9 cases, 5.4%), Basin form (7 cases, 4.2%), Total deaf (24 cases, 14.55%) and Others (10 cases, 6%). 2. In age distribution, the highest is in 3rd decade (50 cases, 30.3%), and the next is in 2nd (43 cases, 26%), 4th (27 cases, 16.3%) in order. 3. Male (101 cases) is more than female (64 cases) giving ratio of 1.9 : 1 4. Bilateral involvement is in 58 cases and unilateral is in 77 5. 45 cases (27.3%) in duration of hearing loss is as short as 3 months and the next is overs; 28 cases (16.9%) 6 to 10 years; 21 cases (12. 7%). And in cases of total deaf, nearly all cases is over 10 years. 6. The suspected cause of the hearing loss is unknown (99 cases, 60%) and the next is following head trauma by traffic accidents in 31 cases (18.8 %) and is related to the middle ear diseased in 12. cases (7.3%). Other causes like senile, noise etc. are in few. 7. The most common findings in ear drums is normal in 177 ears (79.4%) and the next is retracted drums in 28 ears (12.6%). 8. The average hearing level is widely distributed from mild to profound hearing loss which was not related to the audigraphic pattern.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.858-862
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• 2018

The purpose of this study is to improve the current vessel departure control regulations to prevent traffic congestion after the lifting of vessel departure controls due to restricted visibility. AIS data was collected to analyze the traffic volume of normal traffic flow and after departure control. A statistical test was conducted to confirm the difference in traffic volume at peak hours according to whether or not departure control was used. The results of the t-test showed that there was a significant difference in traffic volume among groups of less than 10,000 tons in gross tonnage. However, the Mann-Whitney test showed no difference in traffic volume regardless of vessel control. Small and medium-sized vessels of less than 10,000 tons after departure control increased in traffic volume by 142% over normal traffic, and it was concluded that traffic congestion resulted as these small and medium-sized vessels were departing at the same time as large vessels of more than 10,000 tons. In order to prevent vessel collision accidents due to traffic congestion, it is suggested that the navigability of vessels less than 160 m or less than 10,000 tons should be improved.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.565-575
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• 2009

In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast load is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, normal strength concrete structures require higher strength to improve their resistance against impact and blast loads. Therefore, a new material with high-energy absorption capacity and high resistance to damage is needed for blast resistance design. Recently, Ultra High Strength Concrete(UHSC) and Reactive Powder Concrete(RPC) have been actively developed to significantly improve concrete strength. UHSC and RPC, can improve concrete strength, reduce member size and weight, and improve workability. High strength concrete are used to improve earthquake resistance and increase height and bridge span. Also, UHSC and RPC, can be implemented for blast resistance design of infrastructure susceptible to terror or impact such as 9.11 terror attack. Therefore, in this study, the blast tests are performed to investigate the behavior of UHSC and RPC slabs under blast loading. Blast wave characteristics including incident and reflected pressures as well as maximum and residual displacements and strains in steel and concrete surface are measured. Also, blast damages and failure modes were recorded for each specimen. From these tests, UHSC and RPC have shown to better blast explosions resistance compare to normal strength concrete.

• Journal of Trauma and Injury
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• v.18 no.2
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• pp.81-86
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• 2005

Background: Cardiac troponin I (cTnI) is a sensitive cardiac marker of myocardial injury. In normal coronary angiogram, positive cTnI values may be detected in various events such as sepsis, stroke, trauma and so on. To investigate characteristics of cTnI positive group in trauma patients, we designed this study between cTnI positive group and cTnI negative group. Method: Trauma patients who visited emergency room within 24 hours after accidents were included. Patients who had renal failure, acute coronary syndrome, sepsis, spontaneous SAH were excluded. Retrospective study of 97 trauma patients was done. We investgated ISS (injury severity score), positive cTnI, EKG abnormality, shock class, ICU admission rate and mortality. Result: In comparing with non chest trauma group, chest trauma group, whose chest AIS (Abbreviated Injury Score) is more than 3 point, had significant values in ISS, positive cTnI, EKG abnormality, shock class and ICU admission rate. Also, in non chest trauma group, we found several patients whose cTnI level was positive. When non chest trauma group was divided into two subgroups, the mortality and shock class of positive cTnI group were higher than that of negative cTnI group. When all trauma patients were divided into two groups, a positive cTnI group had higher values in ISS, shock class, ICU admission rate and mortality than that in a negative cTnI group. Conclusion: We found that cTnI were positive in patients of cardiac contusion but also in various trauma cases. In non chest trauma patients, we assumed that hypotension caused cTnI elevating. The cTnI could play a role in predicting prognosis in trauma patients.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.525-538
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• 2014

Safety of reactive systems is one of the most important research areas in the field of weapon development. A NoGo response or at least a low-order explosion should be ensured to prevent unexpected accidents when the reactive system is impacted by high-velocity projectile. We investigated the shock-induced detonation of cased reactive systems subject to a normal projectile impact to the cylindrical surface based on two-dimensional hydrodynamic simulations using the I&G chemical rate law. Two types of energetic materials, namely LX-17 and AP-based solid propellant, were considered to compare the dynamic responses of the reactive system when subjected to the threshold impact velocity. It was found that shock-to-detonation transition phenomena occurred in the cased LX-17, whereas no full reaction occurred in the propellant.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.8
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• pp.939-944
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• 2014

Traffic accidents caused by the attention dispersion are increasing and the behavior of the attention dispersion affects the front-observing rate, road keeping ability, and reaction time for a dangerous situation. Many drivers listen to a radio broadcast and they have to change the frequency for continuously listening a radio broadcast of the specific broadcasting station in case of crossing a boundary of the particular area. In this situation, the possibility of a car accident increases, because the attention dispersion of a driver might be occurred. Especially, the risk of a car accident caused by changing the frequency of a radio is more serious in the highway, due to the high speed of a vehicle. In order to reduce the risk of a car accident caused by handling a radio during driving car, in this paper, we propose an automatic frequency conversion algorithm for vehicle radio, which saves normal system frequencies of primary broadcasting stations in a database and determines new frequency of the changed area using the location information obtained from a navigation system in a boundary of the specific area. After determining new frequency, the proposed algorithm selects a frequency with better receiving rate comparing signal-to-noise ratios (SNRs) of two signals corresponding previous and new frequencies.