• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.11
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• pp.991-998
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• 2010

The effect of increasing the elevation of an IHX (intermediate heat exchanger) on the transient performance of the KALIMER-600 reactor pool during the early phase of a loss of normal heat sink accident was investigated. Three reactors equipped with IHXs that were elevated to different heights were designed, and the thermal-hydraulic analyses were carried out for the steady and transient state by using the COMMIX-1AR/P code. In order to analyze the effects of the elevation of an IHX between reactors, various thermal-hydraulic properties such as mass flow rate, core peak temperature, RmfQ (ratio of mass flow over Q) and initiation time of decay heat removal via DHX (decay heat exchanger) were evaluated. It was found that with an increase in the IHX elevation, the circulation flow rate increases and a steep rise in the core peak temperature under the same coastdown flow condition is prevented without a delay in the initiation of the second stage of cooling. The available coastdown flow range in the reactor could be increased by increasing the elevation of the IHX.

• Research in Plant Disease
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• v.18 no.3
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• pp.217-224
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• 2012

Post-harvest rot of grape causes a severe economic loss and lower of the grape quality. It is also one of the important limiting factors for grape export. Grape rots and their casual agents on 'Red Globe' variety imported from Chile were identified. Grapes shown rotting symptom were collected from the storages near the import harbor. The 3 different rots were identified on the imported 'Red Globe'; melting decay, gray mold, and blue mold. A bacterium that isolated from a typical melting decay symptom was identified as Gluconobacter cerinus on basis of its nucleotide sequence of 16S rDNA and fatty acid profile. By inoculation on grape, it caused cracking and dissolution of epidermis of grape which were the characteristics of melting decay. Botrytis cinerea and Penicillium expansum were isolated from grapes showing gray mold and blue mold. The 2 fungal isolates were identified on basis of their morphological characteristics and nucleotide sequence of their beta-tubulin genes. They showed strong pathogenicity on 'Campbell Early' variety that is a major table grape in Korea.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.552-560
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• 2010

$GA_{4+7}$+BA, a plant growth regulator for induction of feathering in young apple tree and increasing fruit size, was applied by various methods on 'Gala'/M.9 apple trees in high density orchard for 4 years to investigate its effect on fruit and shoot growth. $GA_{4+7}$+BA($80-300mg{\cdot}L^{-1}$) increased fruit length, fruit weight, and L/D ratio regardless of application methods, but it did not affect soluble solid content, acidity, leaf area, and chlorophyll. Seed number was not affected by $GA_{4+7}$+BA application, however, more immature seeds was observed in treated 'Gala' fruit. Shoot growth was increased when spraying $GA_{4+7}$+BA at tree crown but not affected when spraying at fruit directly. More significant fruit growth was observed when $GA_{4+7}$+BA was applied on the fruits between late of May and early of June when fruit cell division ended; however, high concentration of $GA_{4+7}$+BA resulted in lower fruit storability because of lower firmness. Hence, more attention should be paid when applying high concentration of $GA_{4+7}$+BA to small sized fruit cultivars like 'Gala'.

• Journal of Korean society of Dental Hygiene
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• v.1 no.2
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• pp.201-211
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• 2001

Dental caries causes the majority of tooth loss among Koreans. Korea is experiencing an increase in dental caries. And it shows a high prevalence of caries in preschool children, which contrasted with the much-improved situation in developed countries. So, it is important to control caries from preschool periods in Korea. Recently, inspections of the teeth of preschool children for evidence of dental disease became a legislative duty in Korea following Oral Health Act(2000). But, standardized oral health programs in preschool children is not yet proposed. Therefore, it is necessary to develop an community based oral health program in preschool children. The purpose of this study was to obtain basic data for the development of community based oral health program in preschool children of Sungnam city. Oral health status in primary dentition were surveyed in 862 2-6 year-old preschool children of Sungnam city by WHO criteria. From the data, df rate, percentage of preschool child ren with active caries, dft index, dt rate, percentage of preschool children with pit and fissure sealant of each age were calculated, and discussed. The obtained results were as follows : 1. The experience of dental caries in primary dentition showed a tendency to increase quickly between 2 and 3 year old children. So, the oral health program in preschool children should be developed to prevent dental caries and control their oral health under three years of age. 2. In 5 year-old children, the percentage with active caries was 60.8% and dft index was 5.06. The dt rate showed a tendency to decrease as proportion to age, but even though 6 year-old children, the dt rate was 47.7%. Therefore, the annual screening dental examination and oral health education programs at the institution for preschool children should be developed to detect and treat dental caries in primary dentition at early stage. 3. The percentage of preschool children with pit and fissure sealant at six years of age was 10.2%. So, pit and fissure sealant and professional fluoride application programs in Public Health Center should be developed to prevent dental caries. 4. Also, it is necessary to establish oral health goals in preschool children and develop water fluoridation program 10 improve and preserve oral health of preschool children in Seongnam city, effectively.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.577-582
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• 2011

Greenhouse satsuma mandarins (Citrus unshiu Marc., cv. Gungchun) of an early harvesting cultivar were treated by hot water showering at 65$^{\circ}C$ for 10 s at a commercial scale in a packing house and then stored at 5$^{\circ}C$ for 3 weeks and subsequently at 18$^{\circ}C$ for 1 week (simulated shelf-life) to examine the potential use of hot water treatment (HWT) as an environmentally benign method to maintain mandarin quality characteristics during postharvest storage and sale. The respiration rate just after heat treatment or during storage was at a similar level in both the treated and untreated fruit. HWT also had no detrimental effects on quality attributes including pH, titratable acidity, soluble solids content, weight loss, firmness, and peel color. The development of stem-end rot, mold decay, and black rot was lower in the heat-treated fruit compared to those in the untreated control. A sensory evaluation showed that HWT markedly improved fruit appearance, making the fruit cleaner and glossier. The results suggested that HWT can be applied to satsuma mandarin as an effective pretreatment to maintain postharvest quality during storage and marketing.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.478-486
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• 2017

To find the effect of packaging materials(LDPE $60{\mu}m$, Ceramic $30{\mu}m$ and $60{\mu}m$) to enhance the shelf-life of de-astringent persimmon, the fruits used were the astringent persimmons of "Cheongdobansi" and astringency was removed in $CO_2$. De-astringent persimmon were stored in MA for 140 days at $5^{\circ}C$. During storage, the concentration of oxygen was decreased to 5.2%, while the concentration of carbon dioxide was increased to 5.2% from 18 days. But the concentration of oxygen and carbon dioxide was maintained at a constant concentration until the end of storage. The rate of weight loss was gradually decreases for the storage time elapsed and has better in ceramic $60{\mu}m$ packaging than other packaging materials. Fruit hardness and color value were well maintained in ceramic $60{\mu}m$ packaging. Tannin content and soluble solid were not significant difference among the packaging conditions. Ethanol and acetaldehyde content were decreased during early period of storage and then increased. As a result of objective analysis, de-astringent persimmon storage in ceramic $60{\mu}m$ was more effective than other storage conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.257-265
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• 2020

Parts obsolescence is a component type, in which raw materials or parts that make up a weapons system, are developed and produced according to demand, but they age due to changes in technology or market conditions. The weapon system equipment currently being used by the military is having difficulty in procurement, maintenance, and operation because of the obsolescence of parts. Parts obsolescence during the life cycle of a weapons system affects not only the combat readiness of the military but also the economic loss of material, parts, and equipment manufacturers and suppliers. On the other hand, advanced technology has reduced the life span of electronic components that make up the weapons system. In addition, because of the nature of the weapons system, the obsolescence of components takes decades from development to disposal, which has a serious adverse effect on equipment readiness and life cycle costs. Therefore, it is necessary to manage systematically the parts obsolescence from development until the disposal of the weapons system equipment. This study examined the system of component control in developed countries to present a proper management plan for local situations and propose development plans for the early settlement of component control.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.127-131
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• 1999

Avulsion fractures of the intercondylar eminence of the tibia are not uncommon. In the displaced avulsion fracture, anatomical reduction and firm fixation of fracture fragments are needed but the most of the conventional operative techniques including arthroscopic technique are relatively complex and need. The results were not always satisfactory due to the risk of postoperative complications such as wound infection, premature epiphyseal closure and loss of fixation after early motion etc. So we describe a simple and safe modified method of arthroscopic reduction and fixation for avulsion fractures of the intercondylar eminence of the tibia. In our thirteen cases, we achieved anatomical reduction and secure fixation using cannulated screw through the three arthroscopic portals (anterolateral, medial mid-patellar and central). Postoperatively, immediate limited range of motion of the knee and partial weight bearing were possible. Additional use of the washer afforded safe fixation of comminuted avulsion fracture. The advantage of this technique includes its technical simplicity, easy removal of hardware, ability to treat comminuted type IV fracture with washer, no additional skin incision, no damage to growing plate in growth children and less morbidity.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1274-1278
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• 2003

Syncope in children and adolescents have a common occurrence according for up to 15% before adulthood. Micturition syncope, a kind of situational syncope, can be considered a form of reflex syncope. It can typically occur in healthy young men after rising from bed in the early morning who experience sudden loss of consciousness during or immediately after urination. The mechanism of micturition syncope is not completely understood, but it has been suggested that vasovagal reflex mediated bradycardia and peripheral vasodilation and decreased venous return due to Valsalva effect and standing position lead to the decrease in cerebral blood flow resulting in syncope. The causes of syncope are variable. So complete history taking, physical examination, electrocardiography, exercise stress test, echocardiography, head-up tilt table test, electroencephalography(EEG), brain magnetic resonance image and urodynamic study should be required for the diagnosis of micturition syncope. There were several reports about micturition syncope. However, literature of micturition syncope at the pediatric age has rarely been reported in Korea so far. Therefore, we report a case of a 9-year-old boy with micturition syncope with typical EEG findings of high amplitude delta wave and flattening during syncope.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.833-841
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• 2004

This paper treats optimal route assessment system at seaway based on weather forecasting and wave measurement through observation Since early times, captain & officer have been sailing to select the optimum route considering the weather and ship status condition empirically. However, it is rare to find digitalized onboard route support system whereas weather fax or wave and swell chart are utilized for the officer, based on officer's experience. In this paper, optimal route assessment system which is composed of voyage efficiency and safety component is introduced. Optimum route minimized ETA(estimated time of arrival) and fuel consumption is evaluated for efficient voyage considering speed loss and power increase based on wave added resistance of ship. In the view point of safety, seakeeping prediction is performed based on 3 dimensional panel method. Basically, the weather forecast is assumed to be prepared previously in order to operate this system.