• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.435-441
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• 2017

Studies on self-healing have currently been diversified and the methods to evaluate the studies have become more diversified as well. Among them, the back-scattered electron (BSE) image acquired through the scanning electron microscope (SEM) is attempted as the means to evaluate the self-healing effect on cracks. In order evaluate by the BSE image, sophisticated pre-processing of specimen is critical and this injected inside the particle, pore and artificial crack of the hardener to stabilize the structure of the newly generated self-healing product and it enables to endure the stress on polishing without deformation. The impregnated specimen smoothen the surface to obtain the BSE image of high resolution that polishing is made for diamond suspension for wet polishing after dry polishing. As a result of evaluating the self-healing product on the impregnated and polished self-healing specimen, the generated product is formed from the surface of the artificial crack and the self-healing substances are confirmed as $Ca(OH)_2$ and C-S-H.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.39 no.3
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• pp.18-31
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• 2002

In this study, we introduce a concept of advanced neurofuzzy polynomial networks(ANFPN), a hybrid modeling architecture combining neurofuzzy networks(NFN) and polynomial neural networks(PNN). These networks are highly nonlinear rule-based models. The development of the ANFPN dwells on the technologies of Computational Intelligence(Cl), namely fuzzy sets, neural networks and genetic algorithms. NFN contributes to the formation of the premise part of the rule-based structure of the ANFPN. The consequence part of the ANFPN is designed using PNN. At the premise part of the ANFPN, NFN uses both the simplified fuzzy inference and error back-propagation learning rule. The parameters of the membership functions, learning rates and momentum coefficients are adjusted with the use of genetic optimization. As the consequence structure of ANFPN, PNN is a flexible network architecture whose structure(topology) is developed through learning. In particular, the number of layers and nodes of the PNN are not fixed in advance but is generated in a dynamic way. In this study, we introduce two kinds of ANFPN architectures, namely the basic and the modified one. Here the basic and the modified architecture depend on the number of input variables and the order of polynomial in each layer of PNN structure. Owing to the specific features of two combined architectures, it is possible to consider the nonlinear characteristics of process system and to obtain the better output performance with superb predictive ability. The availability and feasibility of the ANFPN are discussed and illustrated with the aid of two representative numerical examples. The results show that the proposed ANFPN can produce the model with higher accuracy and predictive ability than any other method presented previously.

• International Journal of Human Ecology
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• v.2 no.1
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• pp.95-110
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• 2001

The purpose of this research is to analyze how appropriately the sizing of domestically produced children's wear compares to children's sizes; it is based on an anthropometric survey conducted in 1998. By discovering and understanding discrepancies between the sizing system of children s wear and the real size of children, this study aims to suggest solutions that will lead to increased comfort and more suitable fitting in children's clothes. This research analyzes and compares 'the extent of growth between age groups' with 'the difference in sizing system in use by manufacturers'. The study focused on aged 4 to 12 children, who are usually divided in two groups; primary students and toddlers. In total, seven sizes were selected: bust, waist, and hip (which are girth sizes), and height, back neck to waist (top length), sleeve length, and waist to ankle (slacks length) as representing length. The results of this research are analyzed by basing on the actual increments between the sizes of children's wear in certain basic items rather than sizes themselves because each size quite differed according to companies, items and designs. Significantly, the increase in the sizing was not as great as the average biennial growth rate of children. The consequences are poorer fit and unsuitable representative value for each age group because the actual sizes of children increasingly differ from the sample size. Observing the increments in several sizes, we found that 81.8% of the companies used the certain and equal increases for grading sizes in sleeve length, waist, and bust. In addition, 72.7% of the companies adopted the same increments between sizes in height and hip girth, and 63.6% also chose equal increments in T-shirt length for making smaller or bigger sizes from the sample size. However, sleeve length and pant length were the components that displayed the most varied sizing. Interestingly, the few companies that used different increments between size groups, adopted the change only between one or two size groups, instead of all sizes. In conclusion, this research reveals the unsuitability of the current sizing system and the necessity to increase consumer confidence in the size tags on children's wear by modifying the system to reflect the actual growth of children. The results can also contribute to future study on the development of a new and more accurate sizing system for children's wear.

• Physical Therapy Korea
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• v.19 no.1
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• pp.1-9
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• 2012

The purpose of this study was to investigate the kinematic and kinetic changes that may occur in the pelvic and spine regions during cross-legged sitting postures. Experiments were performed on sixteen healthy subjects. Data were collected while the subject sat in 4 different sitting postures for 5 seconds: uncrossed sitting with both feet on the floor (Posture A), sitting while placing his right knee on the left knee (Posture B), sitting by placing right ankle on left knee (Posture C), and sitting by placing right ankle over the left ankle (Posture D). The order of the sitting posture was random. The sagittal plane angles (pelvic tilt, lumbar A-P curve, thoracic A-P curve) and the frontal plane angles (pelvic obliquity, lumber lateral curves, thoracic lateral curves) were obtained using VICON system with 6 cameras and analyzed with Nexus software. The pressure on each buttock was measured using Tekscan. Repeated one-way analysis of variance (ANOVA) was used to compare the angle and pressure across the four postures. The Bonferroni's post hoc test was used to determine the differences between upright trunk sitting and cross-legged postures. In sagittal plane, cross-legged sitting postures showed significantly greater kyphotic curves in lumbar and thoracic spine when compared uncrossed sitting posture. Also, pelvic posterior tilting was greater in cross-legged postures. In frontal plane, only height of the right pelvic was significantly higher in Posture B than in Posture A. Finally, in Posture B, the pressure on the right buttock area was greater than Posture A and, in Posture C, the pressure on the left buttock area was greater than Posture A. However, all dependent variables in both planes did not demonstrate any significant difference among the three cross-legged postures (p>.05). The findings suggest that asymmetric changes in the pelvic and spine region secondary to the prolonged cross-legged sitting postures may cause lower back pain and deformities in the spine structures.

• Ocean and Polar Research
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• v.31 no.2
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• pp.199-212
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• 2009

The community structure of meiofauna was surveyed from six stations in sand mining area near around Sungapdo, Taean five times from April-December, 2007. Ten meiofaunal taxa in total, comprising 5-9 taxa per station were recovered. Nematodes were dominant from four stations in April and from five stations in May. In June, copepods were dominant from all stations except station two, from which sarcomastigophorans were predominant. Copepods were also dominant from three stations in October and four stations in December. The mean density of meiofauna per $10\;cm^{-2}$ was the highest in October (130 individuals) and lowest (68 individuals) in April. Meiofauna mean biomass per $100\;cm^{-2}$ was $3.80-75.26{\mu}gC$ from each station, with the monthly mean biomass being lowest in April ($11.97{\mu}gC$) and highest in October ($39.50{\mu}gC$). The highest biomass was recorded at station five in October ($75.26{\mu}gC$). Eleven families of harpacticoid copepods occurred Ameiridae and Ectinosomatidae were the most frequent. The mean diversity index was 1.21 from all the stations, 1.22 from the sand mining stations, and 1.19 from the reference stations. The nematode:copepod (N/C) ratio was 1.57 from the sand mining stations and 1.37 from the reference stations. Non-metric multidimensional scaling analysis divided the community into group A (station one, non-sand mining and reference area) and groups B and C in the sand mining area. The present study reports similar numbers of taxa but lower density and biomass of meiofauna compared to previous studies in Korean waters. The variability of the diversity index and N/C ratio may indicate large fluctuation of meiofauna depending on temporal and spatial conditions of the environment in the study area.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.185-194
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• 2012

Deepwater oil is becoming more attractive because most onshore and shallow water oil is developing or developed. With the on-going trend to deepwater oil developments, flow assurance problems which prevent oil flow from reservoir to processing facilities are becoming an issue because deposited material can be occurred in case oil is exposed to very different environment from reservoir. Wax deposition which is one of flow assurance problems can be a major technical and economic issue because it is very sensitive to temperature. In order to predict and mitigate wax problems, the precise measurement of wax appearance temperature (WAT) which is the starting temperature of wax precipitation is very important. Various methods have been suggested for WAT measurement of opaque oil because there is no standard method for opaque oil. In this study, the WAT of opaque oil samples was measured using viscosity measurement method, differential scanning calorimetry, filter plugging method, and pressurized filter plugging method. Wax deposition test and high temperature gas chromatography analysis were applied to verify measured WAT. As a result of study, the WAT of opaque oils was successfully measured and verified. If WAT measurement methods of opaque oil related to oil characteristics is systematized using the results of this study, it can be a valuable tool for WAT measurement of opaque oil and flow assurance related to wax deposition.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.339-345
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• 2013

The objective of this study was to establish genetic evaluation systems with carcass data collected by 68 individual farms from 2007 to 2011 in Pyeongchang area of Kangwon province. All the possible of environment effects were corrected by analysis of variance (ANOVA) to estimate more accurate genetic parameters. Heritabilities and genetic correlations were estimated from carcass data collected from Hanwoo steers(n=10,441) born in Pyeongchang region from 2005 to 2008. Traits evaluated included carcass weight (CWT), eye muscle area (EMA), back fat thickness (BF) and marbling score (MS). As for the mean value and standard deviation for carcass traits, CWT, EMA, BF and MS were 424.5, 92, 13.7 and 5.7. Parameters were estimated using a multiple trait animal model and derivative-free restricted maximum likelihood procedures. Estimated heritabilities for CWT, EMA, BF and MS were 0.30, 0.21, 0.42 and 0.42, respectively. Genetic correlation of CWT with EMA, BF and MS were estimated to 0.24, 0.36 and 0.07, respectively. Genetic correlation of EMA with BF and MS was -0.27 and 0.61, respectively.

• Journal of dental hygiene science
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• v.8 no.1
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• pp.35-42
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• 2008

This survey was compared and analyzed about the primary factor that dental office's working environment effect on physical subjective symptom and based on self-filling survey, 656 dental hygienists on July through August 2006, and analyzed using descriptive statics, ANOVA and Multiple Regression Analysis. The result of satisfaction degree of hospital working environment was pretty low about office air condition. Most people have complained that office's air quality makes it difficult to their work and mentioned that they were sore and dull all over the back, shoulder, and neck. The odor is major factor to be satisfied with office environment. Proper ventilates the way open the window more often was essential to maintain fresh indoor air quality and keep the extraction materials by separator and sealing tightly for remove the odor. Other factors were temperature, lighting fixture, ventilation facilities, and freshness of air. Dental hygienist was unsatisfied with hospital air condition and this polluted air condition was the cause of physical subjective symptom in work place. Furthermore, this research would be applied for improvement of working environment by decreasing of indoor air pollution.

• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.361-369
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• 2006

This study conducted an initialization test to decide dynamic position using AHRS IMU sensor, and derived attitude correction angles of vehicles against time through regression analysis. It was also found that the heading angle was stabilized with variation less than 1°after 60 seconds. Using these angles, this study carried out an experiment on the determination of dynamic position for each system in the open sky and in a semi-open sky. According to the results, in the open sky, DGPS alone systems were excellent in accuracy but poor in data acquisition, so the moving distance was around 12m. In DGPS/IMU combined system, accuracy and data acquisition were satisfactory and the moving distance was around 0.3m. In a semi-open sky, DGPS alone systems were excellent in accuracy in order of DGPS < FIMU < DGPS/IMU according to average and standard errors obtained with exclusion of places where data were not be obtained. The moving distance was the same as that in the open sky. For DGPS, when places where data were not obtainable were divided into Several block and they were compared, the maximum deviation from the trajectory was up to 41.5m in DGPS alone system, but it was less than 2.2m and average and standard errors were significantly improved in the combined system. When the navigation system was applied to surveys and the result was compared with position error 0.2mm under the guideline for digital map, it was possible to work on maps on a scale of up to 1 : 1,000.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.2
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• pp.51-60
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• 2018

This study was conducted to observe the effects of gravity and infra-gravity wave of detached submerged breakwater in the coast of Yeongnang-dong, Sokcho, as analyzing continuous wave data by performing field observations on the front area (W0) and rear area (W1, W2). Wave transmission coefficient ($K_t$) of submerged breakwater was analyzed in two parts, short-period wave (gravity wave) and infra-gravity wave. The wave energy reduction effect was analyzed and compared with the value of the design. In case of above wave height 2.0 m at the front area (W0) of the submerged breakwater, the short-period wave height at point W1 is reduced by about 65% and the short-period wave height at point W2 is reduced by about 59%. The depth of crest of submerged breakwater conducted in a sea area differs from the design, and the wave energy reduction effect is analyzed to be smaller than the design plan. The infra-gravity waves were amplified to 2.11 and 1.71 at the W1 and W2 points, respectively, and the wave height at W2 point was smaller than that at W1 point.