• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.473-481
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• 2010

Maxillary canine impaction is an anomaly often encountered in children. Although it has been reported that the incidence of palatally impacted canines is higher than that of labially impacted ones, it has been found that labial impaction of canines is more common than palatal impaction in Asian populations. In the cases presented here, maxillary canines were guided normally after rapid palatal expansion, followed by modification of root angulation of neighboring lateral incisors in 8-10-year-old children who had maxillary canines suspected of labial impaction. Consequently, the method of modifying the root angulation of the maxillary lateral incisor, combined with rapid palatal expansion, is effective in preventing impaction of an ectopically erupting maxillary canine without resorting to surgical methods.

• The Journal of Korean Academy of Sensory Integration
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• v.8 no.1
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• pp.73-86
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• 2010

Problems in feeding habits could affect various aspects of children including growth, learning, communication, interaction with other children, etc. Oral consumption was defined as a participant opening his/her mouth, accepting food/liquid, and swallowing. A goal of the study is to find a method of evaluation and intervention of a child's feeding habits. Feeding is an important component in the early development of children and may have later consequences in the child's ability to participate successfully in their activities of daily life. Children show personal difference on the foods which they try first because stimuli from the foods are revealed as a mealtime behavior through sensory registration and processing. Feeding problems in sensory processing consist of tactile oversensitivity, oral refusal, tactile undersensitivity, and oral dyspraxia. In order to identify problems of sensory processing among feeding difficulties and plan intervention, the understanding of neurological processing and sensory processing characteristics related to feeding is necessary. Reviewing intervention for feeding problems related to sensory processing is required for an effective approach for feeding and providing better life for children.

• Journal of the Korean Society for Library and Information Science
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• v.39 no.3
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• pp.139-163
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• 2005

Various corpus-based approaches, rhetorical roles of discourse structure, and unifications of similar sentences were applied to construct the automatic Ext/Sums(extracts and summaries). Rhetorical roles of sentences like objective, method, background, result, conclusion, etc. for making elastic Ext/Sums were established and extraction engines according to respective role were prepared. The $90\%$ of Success rate in extracting the important sentences of sample articles was accomplished. Rearranging the selected sentences, it used unification of similar sentences using the cosine coefficient equation, deletion of unnecessary modification and insertion clauses, junction of short sentences, and connection of sentences able to link. They suggest the methods applying rhetorical roles of sentences, meaning and signature of noun and verb in clauses, and cue words and location will be researched to construct the more effective Ext/Sums.

• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.115-122
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• 2000

The development of molecular biology has brought many changes in psychiatry. Molecular biology makes us possible to know the cause of mental disorders that provide the way to prevent the disorders, and to develop various accurate diagnostic and treatment methods for mental disorders. The author discusses the concept, cause, and treatment of mental disorders in the aspect of molecular biology. Importing the methods of molecular biology into psychiatry, we can anticipate to get a number of the goals of psychiatric genetics, including identification of specific susceptibility genes, clarification of the pathophysiological processes whereby these genes lead to symptoms, establishment of epigenetic factors that interact with these genes to produce disease, validation of nosological boundaries that more closely reflect the actions of these genes, and development of effective preventive and therapeutic interventions based on genetic counseling, gene therapy, and modification of permissive or protective environmental influences. In addition to their capacity to accelerate the discovery of new molecules participating in the nervous system's response to disease or to self-administered drugs, molecular biological strategies can also be used to determine how critical a particular gene product may be in mediating a cellular event with behavioral importance. Molecular biology probably enables us discover the environmental factors of mental disorders and allow rational drug design and gene therapies for mental disorders, by isolation of gene products that facilitate a basic understanding of the pathogenesis of these disorders. A specific genetic linkage may suggest a novel class of drugs that has not yet been tried. With respect to gene therapy, the hypothetical method would use a gene delivery system, most likely a modified virus, to insert a functional copy of a mutant gene into those brain cells that require the gene for normal function.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.10
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• pp.56-60
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• 2006

It is essential to predict thermodynamic properties of combustion gas with respect to a propellant mixture ratio for the development of a gas generator for a liquid rocket engine. The present study shows the temperature measurement of exit combustion gas as a function of a mixture ratio through the series of combustion tests of a fuel-rich gas generator with liquid oxygen and Jet A-1. The measurements of dynamic and static pressures, and combustion gas temperatures allowed the estimation of thermodynamic properties like a specific heat ratio, a gas constant, and a constant pressure specific heat of the combustion gas. The comparison of the experimental results with predictions made by interpolation parameters obtained from the modification of the chemical equilibrium code indicates that the interpolation method calibrated using the temperature measurements can be utilized as an effective tool for the initial design of a fuel-rich gas generator.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.5
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• pp.432-439
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• 2015

MEMS solid thruster module is composed of solid thruster and its control board. It was developed for the purpose of an academic research. Therefore, thermo-mechanical design and verification for space usage were not considered in the design phase. To mount it on a cube satellite without any design modification, technical efforts at the system level structure design is required. In this study, we proposed a structural design concept to mount the MEMS thruster module by using brackets for guaranteeing structure safety under launch loads and easier mating and de-mating of MEMS thruster module during test phase. The effectiveness of the design has been verified through structural analysis and vibration test. In addition, electrical connection method using spring pins between MEMS thruster and control board is effective for guaranteeing the structural safety under launch vibration loads.

• Nutrition Research and Practice
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• v.1 no.4
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• pp.321-327
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• 2007

The purpose of this study was to assess the relationship between the mother's interest in weight control and its association with the preschooler's obesity and weight related concerns. This was a cross-sectional study based on 470 parents' self-reports. To score interests in weight control, mothers rated each of 6 items on a five-point Likert scale ranging from disagree (1) to agree (5). The perceptions of mothers' weights and their children's weights, mothers' Body Mass Index (BMI), preschoolers' Weight-Length Index (WLI) (%), and weight-related concerns were determined. The mothers' BMI was significantly correlated with interest scores of weight control in mothers (r=0.632, p<0.001) while their children's obesity was weakly correlated with the mothers' interest scores (r=0.133, p=0.025). Mothers with a high interest of weight control reported higher percentages of family history of obesity than mothers with lower interests (63.2% vs. 36.8%, p<0.001). Two-thirds of the mothers (65.4%) were accurate in their perceptions about their weights. Similarly, 63.7% of mothers knew exactly their children's weight-statuses. Compared with mothers with low interest in weight controls, mothers with high interest in weight control had lower correct-perceptions about their weights (p<0.05) but higher correct-perceptions about their children's weights. More than two-thirds of mothers (85%) reported not worrying about their children's obesity in the future. Only 14.3% of the mothers were satisfied with their current weight statuses. Three-fourths of mothers preferred exercise as an effective weight-control method for their children, 20% preferred diet therapy and 5.5% preferred behavior modification. More girls were overweight / obese, than boys (overweight: 16.1% (girl) vs. 12.8% (boy), obese: 5.4% (girl) vs. 4.5% (boy)). About 40% of overweight girls' mothers had low interests in their weight controls with low correct-perceptions in their children's weights, which suggests possible elevated risk of obesity, especially in girls, in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.20-25
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• 2016

This study addresses a low complexity and lossless frame memory compression algorithm based on block-buffer structure for efficient high resolution video processing. Our study utilizes the block-based MHT (modified Hadamard transform) for spatial decorrelation and AGR (adaptive Golomb-Rice) coding as an entropy encoding stage to achieve lossless image compression with low complexity and efficient hardware implementation. The MHT contains only adders and 1-bit shift operators. As a result of AGR not requiring additional memory space and memory access operations, AGR is effective for low complexity development. Comprehensive experiments and computational complexity analysis demonstrate that the proposed algorithm accomplishes superior compression performance relative to existing methods, and can be applied to hardware devices without image quality degradation as well as negligible modification of the existing codec structure. Moreover, the proposed method does not require the memory access operation, and thus it can reduce costs for hardware implementation and can be useful for processing high resolution video over Full HD.

• Imaging Science in Dentistry
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• v.42 no.1
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• pp.5-12
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• 2012

Purpose : This study was performed to evaluate possible variations in maxillary and mandibular bone texture of normal population using the fractal analysis, particles count, and area fraction in intraoral radiographs. Materials and Methods : Periapical radiographs of patients who had full mouth intraoral radiographs were collected. Regions of interest ($100{\times}100$ pixels) were located between the teeth of the maxillary anterior, premolar, and molar area, as well as the mandibular anterior, premolar, and molar areas. The fractal dimension (FD) was calculated by using the box counting method. The particle count (PC) and area fraction (AF) analyses were also performed. Results : There was no significant difference in the FD values among the different groups of age, gender, upper, and lower jaws. The mean FD value was $1.49{\pm}0.01$. The mean PC ranged from 44 to 54, and the mean AF ranged from 10.92 to 11.85. The values of FD, PC, and AF were significantly correlated with each other except for the upper molar area. Conclusion : According to the results, patients with normal trabecular pattern showed a FD of approximately 1.5. Based on these results, further investigation would be recommended if the FD value of patient significantly differenct from this number, since the alteration of this value indicates microstructural modification of trabecular pattern of the jaws. Additionally, with periapical radiographs, simple and cost-effective, PC and AF could be used to assess the deviation from the normal.

• Journal of Forest and Environmental Science
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• v.36 no.3
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• pp.225-232
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• 2020

Chemical modification of wood is an effective method to enhance the biological durability of wood with no toxic effect on the environment. In this study, wood of Triplochiton scleroxylon was modified using acetylation techniques. A total of one hundred wood blocks, (each 20×20×60 mm) obtained from a 22-year old T. scleroxylon tree were conditioned and acetylated at 120℃ in a bioreactor containing acetic anhydride for 60, 120, 180, 240 and 300 minutes. The percentage weight gain of acetylated wood was determined. The untreated (control) and treated blocks were exposed to Pleurotus ostreatus (white rot fungus) and Fibroporia vaillanti (brown rot fungus) after which moisture content (MC) and weight loss (WL) was monitored for 16 weeks. Data were analysed using descriptive and inferential statistics at p<0.05 level of significance. The percentage weight gain of acetylated wood samples increased with time from 10.4% (60 minutes) to 22.7% (300 minutes). MC of untreated blocks inoculated with Pleurotus ostreatus was significantly higher than those of Fibroporia vaillantii after 16 weeks exposure. There was no significant difference in the MC of the of the acetylated samples for the two fungi after 300 minutes reaction time. The WL of untreated blocks inoculated with Fibroporia vaillantii was higher than those of Pleurotus ostreatus, however, the two fungi showed no significant difference in the WL for the acetylated samples after 16 weeks exposure. Acetylation prevents moisture absorption and inhibition of fungi growth in acetylated wood compared to untreated wood, thereby enhancing the durability of Triplochiton scleroxylon.