• Journal of Korean Neurosurgical Society
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• v.53 no.5
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• pp.269-273
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• 2013

Objective : Posture induced common peroneal nerve (CPN) palsy is usually produced during the prolonged squatting or habitual leg crossing while seated, especially in Asian culture and is manifested by the onset of foot drop. Because of its similarity to discogenic foot drop, patients may be diagnosed with a lumbar disc disorder, and in some patients, surgeons may perform unnecessary examinations and even spine surgery. The purpose of our study is to establish the clinical characteristics and diagnostic assessment of posture induced CPN palsy. Methods : From June 2008 to June 2012, a retrospective study was performed on 26 patients diagnosed with peroneal nerve palsy in neurophysiologic study among patients experiencing foot drop after maintaining a certain posture for a long time. Results : The inducing postures were squatting (14 patients), sitting cross-legged (6 patients), lying down (4 patients), walking and driving. The mean prolonged neural injury time was 124.2 minutes. The most common clinical presentation was foot drop and the most affected sensory area was dorsum of the foot with tingling sensation (14 patients), numbness (8 patients), and burning sensation (4 patients). The clinical improvement began after a mean 6 weeks, which is not related to neural injury times. Electrophysiology evaluation was performed after 2 weeks later and showed delayed CPN nerve conduction study (NCS) in 24 patients and deep peroneal nerve in 2 patients. Conclusion : We suggest that an awareness of these clinical characteristics and diagnostic assessment methods may help clinicians make a diagnosis of posture induced CPN palsy and preclude unnecessary studies or inappropriate treatment in foot drop patients.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1355-1360
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• 2013

A cracked solid propellant would have failure or fracture of rocket because of excessive combustion according to increase of burning area, therefore it is important to evaluate the fracture toughness of solid propellant. A procedure is used to investigate the material under a range of test temperatures between -60 and $60^{\circ}C$, three kind of specimen thickness, 4, 12.5 and 24.5 mm to determine the effect of two parameters on the fracture toughness. A center cracked tension (CCT) specimen is used in these tests, which were conducted using INSTRON 5567 testing machine and environmental chamber to evaluate the fracture toughness. The experimental results show that the fracture toughness tends to decreases with an increase in the temperature, and the effect of thickness indicates that the fracture toughness is highest at 12.5 mm under various temperatures except $-60^{\circ}C$. It is found that the fracture toughness of solid propellant is changed due to glass transition behavior around $-60^{\circ}C$.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.2
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• pp.79-85
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• 2007

An internal ballistic model to predict the performance of a Polyethylene-GOX (PE-GOX) hybrid motor was proposed and evaluated. A theoretical treatment of the model was followed by detail discussion of each of the factors affecting the overall performance. The present model consists of the governing equations by considering the unsteady burn-back rate of the fuel grain and on-off response characteristics of a oxygen-supply valve. The numerical results using the 4th order Runge-Kutta scheme with temporal physicochemical properties showed good agreements with test results and the global effects of the performance parameters, such as the burning area of the fuel grain, O/F ratio, and etc., on the performance of the motor were analyzed.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2101-2108
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• 2008

Most of train fires which occur in usual cases do not grow up significantly on a large scale enough to bring about casualties and harmful damages. However, the consequence of some train fire accidents can be devastating disaster so that it would be even recorded in history in unusual cases. Accordingly, such a probability of fire disaster cannot be ignored in aspect of the railway safety assesment. A scale of injury and damage is very difficult to predict and analyze. Because it is depend on various factors, i.e. fire load, burning period, facilities, environment condition, and so on. Thus, a prediction of fire load could be understood as a one methodology to estimate railway safety assesment. The summation method which is one of them is used to evaluate the overall fire load by assuming that sum of heat release rate per unit area or mass of each composite material equals the total. However, since the train fire is classified into a compartment fire in under-ventilation condition. The summation method do not estimate a fire load completely. In this journal, Various methods to predict fire load are introduced and evaluated. Especially the fire simulation tool FDS(Fire Dynamics Simulator)which is based on the CFD(Computational Fluid Dynamics) is introduced, too. Through the FDS simulation, numerical analyses for the fire load and flame spread are performed. Then, these results of the simulation are validated through the comparison study with the experimental data. Then, limitations and approximations including in simulation process are discussed. The future direction of research is proposed.

• Journal of The Korean Society of Clinical Toxicology
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• v.7 no.1
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• pp.10-18
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• 2009

Purpose: Carbon Monoxide Poisoning is an important medical emergency in Korea, but the factors leading to its serious manifestation are not well studied. Methods: We conducted a 5-year retrospective study of 98 carbon monoxide poisoned patients who visited the emergency departments of the Medical Center between December 2004 and March 2009. We categorized the patients into those exhibiting only local symptoms (group 1) and those showing systemic symptoms and complications (group 2). We compared the general characteristics as well as the clinical and laboratory findings between both groups. Results: The male to female ratio was 1.18. The most common systemic symptom was a mental change (43.9%), while the most common complication was rhabdomyolysis (31.6%). Poisoned area closed private room in group 2 were 23 (41.8%) cases and burning region in group 2 were 16(29.1%) cases (p=0.956). Individuals who were accidentally poisoned comprised of 43 (78.2%) cases while those that attempted suicidal poisoning comprised 12 (21.8%) cases (p=0.016). The most common symptom at arrival was mental change 33 (60.0%) cases in group 2. The mean time exposed to carbon monoxide was 43$\pm$3.97 hours in group 1 and 55$\pm$10.11 in group 2 (p=0.012). The patient's age, context of poisoning, symptom at arrival, and time exposed to the poison were found to be significant risk factors for complications by logistic regression analysis. Conclusion: Carbon monoxide poisoning is an emergency medical condition and the risk factors involved in the development of serious complications must be evaluated.

• Korean Journal of Plant Resources
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• v.15 no.3
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• pp.285-292
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• 2002

This study was carried out to determine agronomic and genetic characteristics of the production process in tropical yams(Dioscorea atata L.). To make clear the possibility of cultivation of tropical yams in the Suwon area, the growth of the aboveground parts and the enlargement of tuber of Dioscorea alata, were investigated. The aboveground parts of the plants whose sprouted mother tuber were planted in late April were grown slowly until the 70-days after planting and grown rapidly after. from about 150-days after plantation, total length of vines slowly decreased due to the burning of the branch vines of lower modes. With regard to the branching progressed to 4th for the solo yam and to 6th for purple yam. The secondary branches tended to grow better. When the formation of daughter tubers was observed at the 50-days after planting, their enlargement was very slow. The rapid growth of tubers began at the 140-days and continued to the 190-days. General components such as protein, fiber, and lipid were higher in D. opposita rather than in D. alata. Hardness of D. alata was 2696.2 while that of D. opposita was 4946.9. Lightness of D. alata was 73.99, being higher than that of D. opposita.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.6
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• pp.1-10
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• 2018

An experimental study was performed for the behavior of the burner flame which results from burning of the liquid hydrocarbon fuel atomized by an ultrasonic transducer. Configurations of the flame and combustion-field were caught by both high-speed camera and thermo-graphic camera, and those images were analyzed in detail through a image post-processing. As a result, the combustion-field grew and reaction-temperature rose due to the strengthening of combustion reaction with the increasing flow-rate of carrier-gas. In addition, a phenomenon of flame flickering was discussed through the comparative analysis of the variational behavior between the visible flame and IR (Infrared) flame-field. Also, the flickering frequency of the flame was confirmed through FFT (Fast Fourier Transform) analysis employing the flame area.

• Journal of Oral Medicine and Pain
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• v.44 no.1
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• pp.1-10
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• 2019

Purpose: The aim of this study was to evaluate the optimal doses of intralesional triamcinolone acetonide (TA) in the treatment of oral lichen planus (OLP). Methods: A randomized clinical trial was performed. Sixty-two lesions of OLP were received 12 mg (group A) or 20 mg (group B) of TA intralesionally weekly for 2 weeks. Subjective symptoms, lesion size, favorable conversion of clinical subtypes, and clinical response were evaluated at weeks 0, 1, 2, and 4. Results: After two consecutive injections of TA, group B showed significant reduction in burning sensation and reticular area (p<0.01). Favorable conversion and complete response were greater in group B. Mild oral candidiasis was developed in group B (10.7%). Conclusions: A 20-mg injection of TA was much more effective compared with 12-mg injection of TA in the treatment of OLP.

• Journal of the Society of Disaster Information
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• v.15 no.1
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• pp.12-19
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• 2019

Purpose: The purpose of the study is to reduce the fire of the same type by analyzing the form which is mainly generated based on the result of the fire investigation through the experiment to reproduce, since the candle fire is repeated every year with the same type. Methods: For the analysis of candle flame, 4 kinds of methods such as acrylic recharge test, FOMEX acrylic recharge test, general combustible recharge test, and natural fire extinguishing test of candle were conducted. Results: It was confirmed that continuous burning is difficult to be achieved without contact of combustible materials around. Conclusion: In order to prevent a candle fire, it is important to check the safety of the surrounding area. It is also considered to introduce safety regulations such as finishing with a fireproof material such as a silver foil at the terminal end.

• The Korean Journal of Pain
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• v.35 no.4
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• pp.468-474
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• 2022

Background: The new type of corona virus has a wide range of symptoms. Some people who have COVID-19 can experience long-term effects from their infection, known as post-COVID conditions. The authors aimed to investigate prolonged musculoskeletal pain as a symptom of the post-COVID-19 condition. Methods: This is a descriptive study on the patients who were diagnosed with COVID-19 in a university hospital, between March 2020 and March 2021. Patient records and an extensive questionnaire were used to obtain relevant demographic and clinical characteristics, including hospitalization history, comorbidities, smoking history, duration of the pain, the area of pain, and the presence of accompanying neuropathic symptoms. Results: Of the diagnosed patients, 501 agreed to participate in the study. Among the participants, 318 had musculoskeletal pain during COVID-19 infection, and 69 of them reported prolonged pain symptoms as part of their a post-COVID condition which could not be attributed to any other cause. The mean duration of pain was 4.38 ± 1.73 months, and the mean pain level was 7.2 ± 4.3. Neuropathic pain symptoms such as burning sensation (n = 16, 23.2%), numbness (n = 15, 21.7%), tingling (n = 10, 14.5%), stinging (n = 4, 5.8%), freezing (n = 1, 1.4%) were accompanied in patients with prolonged musculoskeletal pain. Conclusions: Patients with COVID-19 may develop prolonged musculoskeletal pain. In some patients, neuropathic pain accompanies it. Awareness of prolonged post-COVID-19 pain is crucial for its early detection and management.