• Korean Journal of Environment and Ecology
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• v.25 no.1
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• pp.17-30
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• 2011

This study has analyzed the vegetation composition in the areas using different slope revetment techniques of riverbanks, in a way to improve the vegetation induction in the future considering the ecological aspects of the induction in Garaeyoul Village, Gangdong-gu, Seoul. The result of the vegetation distribution in each different slope revetment technique was analyzed, that the naturalized herb was dominant in the pole block accounting for 70.7%, while native herb was dominant in the lawn block occupying 48.5% and in the crib block occupying 55.7%. The vegetation coverage measured by different slope revetment techniques was highest in the crib block(average 97.5%), followed by the lawn block(average 95.3%) and pole block(average 27.9%). The vegetation base area was the most wide in the crib block and the most narrowest in the pole block. The result of community analysis in areas using different slope revetment techniques, dry herbs and vine herbs were dominated and the coverage was very poor in the pole block. In the lawn block, the barb was fragmented into narrow areas due to the blocks, which prevented the creation of large-scale plant communities. In the crib block, Miscanthus sacchariflorus, Fescue arundinacea and Aster pilosus, which also consisted of large-scale communities. Average dry weight was also measured by each slope revetment technique. The weight was heaviest in the crib block with $187.63g/m^2$, followed by the lawn block($137.65g/m^2$) and pole block($6.75g/m^2$). The soil moisture contents in the crib block and lawn block was 16.3% and 15.2%, respectively, while that of the pole block was 4.7%, which revealed the highly dry condition of the pole block soil. The analysis result of soil chemical property showed that there was little difference in soil texture, soile acidity(pH), and exchangeable ion content, however, the soil organic matter(OM) content and available $P_2O_5$ were highest in the pole block. In the future, in order to induce more vegetation into river banks and walls, a proper construction method should be applied so that the vegetation area can be expanded as much as possible, considering the safety of the banks.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.229-235
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• 2005

A problem that affects children's dentitions is the harmful habit which is difficult to treat. Harmful habits for children are such as abnormal swallowing patterns, low/forward tongue rest posture problem, habitual open-lips resting posture, habitual mouth-breathing, excessive digital sucking habit and tongue thrusting. Tongue thrusting habits cause a bit of cranio-facial skeletal changes and a great deal of dental malocclusion such as anterior open bite. Anterior open bite causes masticatory, speech, and esthetic problems in the growing children and difficulties in diagnosis, treatment, and the prediction of its prognosis. The treatments of such abnormal behaviors involve orofacial myofunctional therapy and using of habit breaking appliance. The prognosis is not determined by the presence of severity of oral habit but the skeletal tendency of the patient. Usage of tongue crib resulted in not only the discontinuance of the habit but also improvement in overbite and overbite. This study showed that relatively successful results could be generated by using removable tongue crib and myofunctional therapy in the case of openbite related to tongue thrusting habit.

• Journal of the Korean Geotechnical Society
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• v.21 no.1
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• pp.51-58
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• 2005

The use of geogrid for SRW systems and bridge abutment has increased rapidly over the past 10 years in Korea. The concept of segmental retaining walls and reinforced soil is very old and for example The Ziggurats of Babylonia(i.e. Tower of Babel) were built some 2,500 to 3,000 years ago using soil reinforcing methods very similar to those described in current design. Modern SRW(Semental Retaining Wall) units were introduced in 1960's as concrete crib retaining wall systems. In this paper, the friction properties between segmental concrete units and geogrid are investigated by performing various tests.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.13 no.1
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• pp.19-22
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• 2017

Moyamoya disease is characterized by progressive bilateral narrowing of the internal carotid arteries(ICA) and their main branches, and formation of a fine vascular network (moyamoya vessels) at the base of brain. Mild intellectual or motor impairment, or both can be seen in moyamoya disease patient. Patients having intellectual disability usually have malocclusions associated with oral habits such as tongue thrusting, bruxism, or clenching. A patient with moyamoya disease and cerebral palsy visited Chonbuk National University hospital for dental examination. She showed mild openbite on anterior teeth, and had oral habits such as mouth breathing, tongue thrusting, and drooling. She was treated with myofunctional therapy(MFT) whose purpose was to strengthen orofacial muscles. Lip closing force and bite force were recorded to evaluate the muscle tone. Tongue crib was delivered to restrict tongue thrusting habit, since her compliance to the MFT was decreased after 6 months of treatment. With the MFT and tongue crib, the openbite was fairly improved. When myofunctional therapy has difficulty in obtaining good compliances, the treatment should not be effective enough. Although intellectually disabled patients are not compliant enough, thus a habit breaking device should be needed to treat the openbite caused by oral habits, dentist should make an effort to do MFT, since it could reduce a treatment period, and enhance the stability.

• Fire Science and Engineering
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• v.28 no.2
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• pp.20-25
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• 2014

In this study, the extinguishing performance evaluation of wetting agent for wood crib was conducted by using a scale model equipment that we designed. To confirm the optimal conditions of the experiment, a test was changed amount of fire extinguishing water and the number of timber. As a result, the discrimination of the fire extinguishing performance was seen only when 20 pieces of wood and the extinguishing water of 100 mL were used. After evaluating the extinguishing performance of domestic and foreign wetting extinguishing agents under these conditions, a reignition was occurred in only when we used water. In addition, the discrimination of extinguishing performance was seen through the temperature distribution according to the time of watering. Based on the results of this experiment, this study is expected to be able to use as a basis on presenting a method of optimized performance evaluation of wetting extinguishing agent.

• Korean Journal of Environment and Ecology
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• v.21 no.5
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• pp.442-448
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• 2007

This study was carried out to assess the improved aspects of ecological conditions in a small stream, where eco-technological restorations such as gabion-crib mattress arrangement and soil-arresting wicker fence work had already been made up to stabilize the physically and ecologically damaged streambank. Six metrics by diatoms including species richness, Shannon diversity, saprobic index by DAIpo, percent sensitive diatoms, percent of Achnanthes minutissima, dominant index were analysed to assess the ecological integrity of small stream. By generalizing the changed values of six metrics on the stream flow from upper point(ST.1) to lower point(ST.3), it was found that the effect value of ecological condition improvement went up to as much as 33.9% on the average. The results suggested that eco-technological restoration treatment applied to this study is considerably effective for preserving the ecological integrity of small stream.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1562-1571
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• 2005

The use of geogrid for SRW systems and bridge abutment has increased rapidly over the past 10 years in Korea. The concept of segmental retaining walls and reinforced soil is very old and for example The Ziggurats of Babylonia(i.e. Tower of Babel) were built some 2,500 to 3,000 years ago using soil reinforcing methods very similar to those described in current design. Modern SRW(Semental Retaining Wall) units were introduced in 1960's as concrete crib retaining wall systems. In this paper, the friction properties between segmental concrete units and geogrid are investigated by performing various tests.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.132-133
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• 2005

A study to evaluate the fire extinguishing performance of the water mist system inside simulated machinery spaces according to IMO MSC/Circ.668 was performed. Fire tests were conducted inside a compartment having a area 100$m^2$(10m${\times}$10m) with a ceiling height of 10m and door opening of 2m${\times}$2m in size. Test fuels were used heptane, diesel, wood crib and mineral oil. Water mist nozzles were installed downward at ceiling and horizontally at bilge area. All fires in the test were extinguished within 15minutes of system activation and there was no reignition or fire spread.

• Fire Science and Engineering
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• v.17 no.3
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• pp.26-30
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• 2003

This paper presents a study on the analysis for false alarm of heat detector using HRR(Heat Release Rate). And it is represented to threshold value and domain of false alarm. The HRR threshold value of false alarm is calculated to use parameters obtained by small scale fire-experiment. The experiment is conducted to measure detector activation time and flame spread of wood cribs fire, etc. The results show that HRR threshold value of Fixed type detector is 20.24 kW and rate of rise type detector is 13.59 kW, respectively.

• Journal of the Korean Society of Safety
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• v.19 no.1
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• pp.49-55
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• 2004

This study presents an analysis of comparison of P-type fire detection system with fuzzy logic-applied fire detection system. The fuzzy logic-applied fire detection system has input variables obtained by fire experiment of small scale with K-type temperature sensor and optical smoke sensor. And the antecedent part of fuzzy rules consists of temperature and smoke density, and the consequent part consists of fire probability. Also triangular fuzzy membership function is used for input variables and fuzzy rules. To calculate the final fire probability a centroid method is introduced. A fire experiment is conducted with controlling wood crib layer, cigarette to simulate actual fire and false alarm situation. The results show that peak fire probability is 25[%] for non-fire and is more than 80[%] for fire situation, respectively. The fuzzy logic-applied fire detection system suggested here is able to distinguish fire situation and non-fire situation very precisely.