• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.2
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• pp.315-323
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• 2015

The weld scallop has been used for joining T-bars. There are a lot of weld scallops in shipbuilding. It is difficult to perform scallop welding due to the inconvenient welding position. This results in many problems such as porosity, slag inclusion, etc. In this study, a new method is devised to remove weld scallops by incorporating a Ceramic Backing Material (CBM). The weld scallop is removed by an elongation of the v groove. In order to insert a CBM into the groove without a weld scallop, a wedge-shaped CBM is developed. The top side of the developed CBM is similar to the shape of a general back bead. The bottom surface has a saw-toothed shape for cutting at a suitable length. This can be attached to the root side of a face plate using adhesive tape, just like a general CBM. Welding experiments in normal and abnormal conditions are carried out and the possibility of burn-through is examined. This CBM's applicability to shipbuilding is verified.

• International Journal of Korean Welding Society
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• v.1 no.2
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• pp.30-35
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• 2001

Nowadays, repair welding on in-service natural gas pipeline is a matter of primary concern of gas company. The main purpose of this study is to investigate the effects of welding conditions on the allowable heat input for crack-free welds and welds without burn-through onto in-service natural gas pipeline. First of all, single pass weld bead on plates of the various thickness was deposited to evaluate the penetration of weld metal, the depth of heat affected zone and the hardness of repair weld under various welding conditions. Also, finite element analysis has been conducted to validate experimental results of bead-on plate welds and to develop appropriate model for repair welding. The welding experiments of bead-on-plate weld confirmed the influence of plate thickness, heat input and welding process on safety. And, the finite element model was demonstrated by comparing experimental results. The agreement between the computed and measured values was shown to be generally good. Therefore, It is possible to predict the safety of repair welding under various welding conditions with experimental results and finite element analysis model.

• Journal of the Korea Institute of Building Construction
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• v.10 no.3
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• pp.99-111
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• 2010

In recent years, the number of high-rise building construction projects has grown, and the number of construction safety accidents has also been increasing. Therefore, the objective of this study is to propose plans to prevent accidents by systematically organizing accident principles and developing a tree diagram for the process of safety accidents that occur in the construction industry. This study aims to show the diverse characteristics of construction accidents based on KOSHA's annual reports on safety accidents(burial, conflagration, explosion, burn) from 1993 to 2009. To achieve these objectives, in this study we first examined the risk factors for burial, conflagration, explosion, and burn. We then systematically organized the classification viewpoint of accident causes, and suggested a methodology for the rationalization of safety management through an analysis of the primary causes of accidents by work type. The results of this study based on this methodology can be divided into three areas: 1)the types of facilities were divided into 43 categories by analyzing the information of KOSHA's annual reports; 2)the causes of burial, conflagration, explosion, and burn were divided into 63types; 3)the types of work were divided into 29 categories.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.325-337
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• 2007

Illegal slash-and-bum fields and slash-and-bum farmers in Korea had increased in spite of Japanese Joseon Government's strong regulations and clearance measures, and land reform after the 1945 Liberation of Korea until 1970s. This study is to inquire into the necessary and sufficient conditions to disappear entirely the matters from 1974 to 1979 that illegal slash-and-bum fields and slash-and-burn farmers continued long in existence until the early 1970s. The findings are as follows; Firstly, the population pressure to agricultural lands that main factor of generation of illegal slash-and-bum fields had decreased rapidly because the rural populations and less income farmers have decreased after 1967. Especially, the decrease of the rural populations had never seen to the 1970s. It is recognised that the social condition for the success in 1970s. Secondly, the continuous economic growth from the early 1960s enabled the Korean government to solve the matter through the sufficient financial investment from the Government. For example, the gross national product (GNP) and the government budget in 1974 increased around 25 times after 1960. It is recognised that the economic condition for the success in 1970s. Finally, it was enabled to remove the concealment from the slash-and-bum farmers and to monitor illegal re-cultivation thoroughly because the development of forest inventory technique using an aerial photograph and the expansion of road facilities. It is recognised that the technical condition for the success in the 1970s.

• The Korean Journal of Pain
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• v.12 no.1
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• pp.1-7
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• 1999

Background: To study the role of spinal alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors in pain behaviors caused by mild burn, we examined the effect of intrathecal administered ACEA 2085, which has been recently characterized as a high potency competitive AMPA receptor antagonist, on the thermal hyperalgesia state induced by mild burn. Methods: A thermal injury was induced by applying the left hind paw to a thermal surface ($52.5^{\circ}C$) for 45 sec. Thermal escape latency of the hind paw was determined using an underglass thermal stimulus. Thirty min after thermal injury, the paw withdrawal latency (PWL) in injured paw of all groups fell from 10~12 sec to 5~7 sec. At that time, ACEA 2085 (0.01~0.1 mcg) and 6-cyano-7-nitroquinoxalinedione (CNQX, 1~30 mcg) were injected through intrathecal heters in rats with mild burn injury on the right hindpaw. And then, PWL were measured in the both hindpaw every 30 minutes for about three hours. Results: The intrathecal injection of ACEA 2085 produced a dose dependent reversal of the hyperalgesia in the right hindpaw and more potent than CNQX, but had no effect upon the response latency of the normal left hind paw even at the largest doses. All effects were observed at doses that had no significant effect upon motor function. Conclusions: Intrathecal ACEA 2085, highly selective AMPA receptor antagonist produce a dose- dependent reversal of the thermal hyperalgesia evoked mild burn injury. These results suggested that spinal AMPA receptor play an important role in the hyperalgesia induced by mild burn injury.

• Korean Journal of Plant Resources
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• v.35 no.2
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• pp.169-182
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• 2022

This study was conducted to predict the distribution of rare·endemic plants (Sophora koreensis Nakai) in the border forests where wildfire damage occurred and to quantify the damage. For this purpose, we tried to derive more accurate results through forest area damage (NBR) according to the Burn severity of wildfires, damage by tree species type (Vegetation map), and MaxEnt model. For Burn severity analysis, satellite imagery (Landsat-8) was used to analyze Burn severity (ΔNBR2016-2015) and to derive the extent of damage. To prepare the Vegetation map, the land cover map prepared by the Ministry of Environment, the Vegetation map prepared by the Korea Forest Service, and the vegetation survey conducted by itself were conducted to prepare the clinical map before and after the forest fire. Lastly, for MaxEnt model analysis, the AUC value was derived by using the habitat coordinates of Sophora koreensis Nakai based on the related literature and self-report data. As a result of combining the Maxent model analysis data with the Burn severity data, it was confirmed that 45.9% of the 44,760 m² of habitat (predicted) area of Sophora koreensis Nakai in the wildfire damaged area or 20,552 m², was damaged.

• The Korean Journal of Nuclear Medicine
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• v.30 no.1
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• pp.130-138
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• 1996

Bone scan is known to be an effective tool for observing the state of soft tissues and bones of electric burn patients. It is also used for observing the progress of patients after debridement or skin graft as well as deforming to amputate specific body parts. To evaluate bone scan's role in electric burn, we analyzed bone scan 37 patients with electric burn. Among the 37 patients, 8 of 37 were injured in low voltage and 29 of them in high voltage. 27 patients received the electrical input through the hand, 6 through the scalp, 2 through the shoulder, 1 through the left chest wall and 1 through the left inguinal area. Among 29 patients received high voltage, 22 patients had the electrical output through the foot, 3 through the hand, 2 through the shoulder, 1 through the buttock and 1 through the left chest wall. Bone scans revealed cellulitis in 37 patients with 47 sites, osteomyelitis in 15 patients with 15 sites & bone defects in 4 patients with 4 sites. In 4 patients with skin graft or skin flap, follow up bone scan showed improvements of bony uptake in preoperatively bony defect area and all of them were healed without complication. There were 2 cases in which uptake increased in the myocardium, 1 in the liver and 6 in the kidney, however, serum calcium level, EKG, cardiac enzyme, liver and renal function tests were normal. In conclusion, bone scans are helpful in the assessment of injury sites after electrical insult and in differential diagnosis of cellulitis and osteomyelitis. It is also useful tool of assessment after skin graft or skin flap, however, it should be further evaluated about internal organ damage.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.1
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• pp.11-16
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• 2001

Background and Objectives : A burn injury to the glottis differs from a burn injury to the trachea, bronchi, and lung parenchyma, in that thermal injury does not occur to any significant degree below the level of the larynx, due to the effective cooling of air by the upper airway and to reflex closure of the vocal cords from a blast of hot air. Therefore, the laryngeal inhalation injury give rise to airway problem and voice change. The objectives of this study is to assess management of laryngeal inhalation injury and voice change after management. Materials and Methods : Voice choses and laryngeal injuries of eight laryngeal inhalation patients were analyzed through questionnaire, voice dynamic laboratory, and laryngeal stroboscopy. Operative management was performed to five patients for airway patiency and vocal cord movement on laryngeal pathology ind voice therapy was performed to all patients. One-year after, voice changes and laryngeal injuries were reanalyzed with same methods. Results : Vocal breathiness, decreased voice intensity, reduced voice range, and easy fatigability were major complaints of laryngeal inhalation patients. Glottic stenosis were developed to five of eight patients, and vocal cord atrophy, bowing were developed to others. Vocal cord mucosal waves were significantly decreased in all patients. Jitter(%), Shimmer(dB) were increased and Maximal phonation time(MPT) was decreased. One-year after, subjective voice changes and objective voice parameters were improved. And vocal cord mucosal waves were recovered in all patients. Conclusions : Subjective voice quality and objective voice parameters were improved after operative management for laryngeal pathology and voice therapy. And we observed recovery of vocal fold mucosal waves by laryngeal stroboscopy. We think that early preventable tracheotomy is necessary to reduce the laryngeal contact injury in laryngeal inhalation patients.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.10
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• pp.837-844
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• 2014

Automotive manufacturers have recently developed various technologies for improving fuel economy and satisfying enhanced emission regulations. The ultra-lean direct injection engine is a promising technology because it has the advantage of improving thermal efficiency through the deliberate control of ignition. A conventional LPG engine has been redesigned to an ultra-lean-burn LPG direct injection engine in order to adopt combustion system of ultra-lean-burn. This study is aimed at investigating the effect of a change in the compression ratio on the performance and emission characteristics of a lean-burn LPG engine. The fuel consumption, heat release rate, combustion pressure, and emission characteristics are estimated depending on changing the effect of compression ratio. When the compression ratio is increased, it is difficult to improve the fuel consumption owing to an unstable combustion state, but the total hydrocarbon and nitrogen oxide emissions are reduced.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.6
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• pp.529-534
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• 2014

Pyrotechnic devices are widely used for space appendages. However, a cube satellite requirements do not permit the use of explosive pyrotechnic device. A nichrome burn wire release has typically been used for holding and release of deployable appendages of the cube satellite due to its simplicity and low cost. However, relatively low mechanical constraint force and system complexity for application of multi-deployable systems are disadvantages of the conventional mechanism. To overcome these drawbacks, we developed a hinge driving segmented nut type holding and release mechanism based on the nichrome burn wire release. The functional performance of the mechanism has been verified through release function test, static load test and shock level measurement test.