• Polymer(Korea)
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• v.28 no.4
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• pp.285-290
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• 2004

Nondestructive damage sensitivity of carbon nanotube(CNT) and nanofiber (CNF)/epoxy composites with their adding contents was investigated using electro-micromechanical technique. Carbon black (CB) was used only for the comparison with CNT and CNF. The fracture of carbon fiber was detected by acoustic emission (AE), which was correlated to the change in electrical resistance, ΔR under double-matrix composites (DMC) test. Stress sensing on carbon nanocomposites was performed by electro-pullout test under uniform cyclic loading. At the same volume fraction, the damage sensitivity for fiber fracture, matrix deformation and stress sensing were highest for CNT/epoxy composite, whereas for CB/epoxy composite they were the lowest among three carbon nanomaterials (CNMs). Damage sensitivity was correlated with morphological observation of carbon nanocomposites. Homogeneous dispersion among CNMs could be keying parameters for better damage monitoring. In this study, damage sensing of carbon nanocomposites could be evaluated well nondestructively by the electrical resistance measurement with AE.

• Journal of Chest Surgery
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• v.29 no.11
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• pp.1270-1275
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• 1996

Pulmonary artery aneurysms are extremely rare conditions usually associated with congenital cardiac defects that cause increased pulmonary blood flow and pulmonary hypertension. The prognosis of pulmonary artery aneurysms is fatal due to the potential for rupture of the aneurysm and the underlying severe pulmonary hypertension. A 40-year old woman was admitted to our hospital with headache following traffic accident. On admission a continuous murmur was heard over the 2nd to 3rd intercostal space along left sternal border and a calcified cystic mass at left hilar portion was incidentally discoverd on chest reontgenogram. Cardiac catherization was diagnostic of a left to right shunt at main pulmoanry artery level and pulmonary hypertension. Pulmonary angiogram demonstrated a large aneurysm of main pulmonary artery extending into proximal left pulmonary artery. The pulmonary artery aneurysm associated with patent ductus arteriosus was diagnosed definitively and the patient was underwent resection of pulmonary artery aneurysm, closure of PDA and Dacron prosthetic graft replacement under cardiopulmonary bypass. The postoperative course was uneventful and the patient was discharged without any problem.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1174-1179
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• 2006

In order to study auricular acupuncture and treadmill exercise involved in high fat diet-induced obesity rats. Thirty Sprague-Dawley rats which were divided into five group. Group I : Normal diet-induced group, Group II : high fat diet-induced group, Group III: high fat diet-induced group and auricular acupuncture, Group IV : high fat diet-induced group and treadmill exercise, Group V : high fat diet-induced group and auricular acupuncture and treadmill exercise. In each group, body weight, serum lipid, histologic obserations, and fat tissue were observed and analyzed. The following results were obtained. Body weights were significantly increase in group II than group I. The level of total cholesterol, LDL-C and TG were significantly lower in experimental groups than group I. Only auricular acupuncture was tended to body weight change but not significantly different between experimental group. The above result suggest that auricular acupuncture and treadmill exercise effectively repressed in obesity. It would be considered that auricular acupuncture and treadmill exercise have an effects on relieving obesity.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.179-189
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• 2001

This study was performed to identify the current status of work environment management and to provide appropriate recommendations for small scale industry with less than 5 workers from September, 2000 to October, 2000 in Seoul city and Gyoung-gi province. The 211 companies were surveyed by checklist included the elements of management of work environment, hazardous chemicals, MSDS, personal protective equipment, and ventilation system. The proportion of metal products manufacturing and printing industries are 25.6 % and 22.3%, respectively. The daily working hours in printing industry is longer than others. The industries that produce potentially hazardous agents, such as noise, dust, metal, organic solvents, radiation and chemical material are pulp, plating, machinery, and printing, respectively. In above industries, only 2.8 % of those recognised and had MSDS. The proportion of companies providing fire extinguishers, safety showers are found to be 13.3 %, 7.1 %, respectively. Only 24.2 % of companies provided personal protective equipment to the workers. The ventilation system was operated in most of companies. But local exhaust ventilation system is provided to 22.3 % of those, also had not been annually inspected. This study showed that the current status of occupational safety and health was not appropriate for workers in small scale industries. It is suggested that annual physical examination have to be performed, MSDS usage must become widespread, and employer and emplyees in small scale industry should be educated for the treatment and storage of hazardous chemicals to improve the occupational safety and health of the working environment. also, regulatory standard has to be applied to local exhaust ventilation system in small scale industry to improve the working condition.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.2
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• pp.141-146
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• 2006

Vagal nerve stimulation (VNS) has been proposed as a possible way to improve the control of refractory epilepsy. We report the effects following VNS treatment in patients with refractory epilepsy. Seventeen patients with a mean age of 12.8 years, ranging from 5 to 29 years, underwent the implantation of vagal nerve stimulation (Cyberonics, Houston, TX). We reviewed the clinical findings before and after VNS in seizure frequency, number of antiepileptic drugs (AED), and quality of life (QOL). All of the patients had intractable seizures, eleven of the patients had additional medical complications, three had hippocampus atrophy, one had encephalomalacia, five had encephalitis, one had pachygyria, and one had schizencephaly. Thirteen patients had symptomatic partial epilepsies, three patients had Lennox-Gastaut syndrome and one had cryptogenic partial epilepsy. The mean follow up duration was 35 months. The mean reduction of seizure frequency compared with baseline before VNS was 26.1% after 3 months (p<0.005), 41.9% after 6 months (p<0.001), 46.9% after 1 year (p<0.001), and 53% at the latest follow-up (p<0.001). Twelve patients showed an improvement of QOL such as mood, language, alertness, expression, and motor function. The most common side effects were transient hoarseness or voice change or cough, which was detected in six patients (35%) and wound infection in one patient (5%). This study has shown a good anti-seizure effect of VNS, decrease in seizure frequency and improvements in QOL. We concluded that VNS is a beneficial therapy in refractory epilepsy with a non-resectable epileptic focus. Further studies should be focused on the prediction of unresponsiveness and the adjustment of VNS parameters for maximum efficacy in patients with various medical histories.

• Polymer(Korea)
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• v.35 no.6
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• pp.537-542
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• 2011

Fracture behaviors of polycarbonate (PC)/polyestrercarbonate (PEC) blends and their miscibility have been examined to find out the mechanism of ductilie-brittle transition of fracture behavior which would be a main governing factor on the thickness sensitivity of impact strength of PC. $T_g$ measurement showed that PEC with a carbonate content higher than 30 mol% was miscible with PC. In the notched Izod impact test of PC, ductile-brittle transition occurred in the range of 4 to 5 mm thickness. The impact strength of miscible PC/PEC5 blends ductile-fractured in the thin specimens decreased with increasing PEC5 content, which was in accordance with the decrease of elongation at break in tensile test. In the brittle fracture of the thick specimens, the impact strength was well correlated with the plastic zone size in the vicinity of the notch tip.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.113-122
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• 2012

The geomorphic properties of potholes at Naerin River, Inje-gun are analyzed to discover the geosites of DMZ geopark in Gangwon-do. The furrow-type potholes along the river flow are mainly found in the P1 and P2 sites. The P3 site can be divided in to the zones where the furrow-type potholes densely distribute and various types of potholes are scattered, while the various types of small potholes are scattered in the P4 site. After measuring the 44 potholes, the potholes with a U-shaped cross-section, similar directivity with river flow and deposited gravels with in them show large values in length, width, depth and slope. Because the P1 and P2 sites are characteristic in the scales and forms of potholes and show beautiful scapes, it can be suggested that they are suitable for the geosite developments.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.8 no.11
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• pp.17-25
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• 1985

In these days the industrial management are characterized by mass production. Mass production which is not possible without the rationalization in the process of production and the efficient scale of management needs development of technical administration. The object of this study is set up on the rationalization in the process of production. And this rationalization is a means to the aim of industrial management. So as to realize the rationalization in the process of production, we should think on plan of production and the line of balancing in processes of work. The line of balancing is considered as one of very valuable administration methods. The line of balancing that controls capacities and loads so that processes of work might balance in each other makes away with happenings of idleness and stagnation during the process of work As a natural consequence it follows (1) shortening in the period of Production, (2) more efficient, (3) removing the lots of tine and matter, (4) more efficient using in elements for production. Therefore, through the labour productivity and the efficiency of the process of production increased by these effects, the line of balancing was intended to curtail the basic cost. Though the previously said line of balancing could be applied to production, it should not be said that we can completely balance in each lines of work. In other words it is impossible that the line of balancing is completely executed in every lines of work. For that reason, we should arrange the level of balancing in lines. Nowaday, in our country, it is true that the line of balancing is hardly executed at manufacturing industries. Therefore if we execute and apply the line of balancing to manufacturing industries and the larger field as well , we could curtail the basic cost, through which we could reinforce not only the international competative power but increase the labour productivity. As a result, by these effects, we would rationalize the industrial management.

• Journal of Adhesion and Interface
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• v.4 no.1
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• pp.18-27
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• 2003

Interfacial properties and microfailure degradation mechanisms of the oxygen-plasma treated biodegradable poly(p-dioxanone) (PPDO) fiber/poly(L-lactide) (PLLA)composites were investigated for the orthopedic applications as implant materials using micromechanical technique and surface wettability measurement. PPDO fiber reinforced PLLA composite can provide good mechanical performance for long hydrolysis time. The degree of degradation for PPDO fiber and PLLA matrix was measured by thermal analysis and optical observation. IFSS and work of adhesion, $W_a$ between PPDO fiber and PLLA matrix showed the maximum at the plasma treatment time, at 60 seconds. Work of adhesion was lineally proportional to the IFSS. PPDO fiber showed ductile microfailure modes at We initial state, whereas brittle microfailure modes appeared with elapsing hydrolysis time. Interfacial properties and microfailure degradation mechanisms can be important factors to control bioabsorbable composites performance because IFSS changes with hydrolytic degradation.

• Journal of Korean Society of Rural Planning
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• v.25 no.1
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• pp.51-65
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• 2019

This study developed diagnostic system to understand the level of welfare cultural service and infrastructure in rural areas. The applicability was reviewed through the Delphi survey and the sample survey of 60 villages. The diagnostic indicators consist of three areas: the demand area, supply area, and delivery area. The demand area consists of 8 indicators, 25 indicators for welfare services and infrastructure (healthcare, social welfare) and 32 indicators for cultural services and infrastructure (culture, education, leisure sports). The service delivery area was divided into service supply area access and traffic accessibility (public transport use status and rural transport model status) by each indicator. A diagnostic system was applied to 60 villages. Services and infrastructure for rural welfare and culture were supplied more in the Si area than Gun area. The delivery area was easier to access the Gun area than Si area. In the case of traffic access, public transportation was more frequently used in the Si area than Gun area, and the rural transportation model was found to have a relatively large amount in the Gun area compared to Si area. The diagnosis system about services and infrastructure for rural welfare and culture will provide information necessary for establishment and decision making of regional development policy taking into account characteristics of rural areas in the future.