• Korea journal of population studies
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• v.8 no.1
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• pp.87-117
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• 1985

In Principle, the distriction should be understood between projections and forecasts. When the author or user of a projection is willing to describe it as indicating the most likely population at a give date, then he has made a forecast Population change since 1 960 has been reviewed briefly in order to forecast the population of Korea in the year 2,000 which is a leading factor in long term national development plan for which Korea Institute for Population and Health (KIPH) has been participated since 1983. The author of this paper introduced the population forecast prepared for the long term national development plan and an attempt of comparisons with other forecasts such as D.P. Smith's, T. Frejka's, Economic Planning Board's (EPB), UN's and S.B. Lee's was made. Those six forecasts of Korean future population in year 2,000 varried from 48.5 million to 50.0 million due to the base population and assumption of fertility and mortality however the range of total population size is not large enough. Taking four forecasts such as KIPH, EPB, UN, and Lee based on 1980 population census results and latest data of fertility and mortality, KIPH and UN forecast are close in total population size even though there was a slight difference in fertility and mortality assumptions. The smallest size of total population was shown by S.B. Lee (see Table 13) although the difference between KIPH and Lee was approximately one million which is two percent of total population in year 2,000. As a summary of conclusion the author pointed out that one can take anyone of forecasts prepared by different body because size and proportion wise of the Korean population until early I 990s can not be different much and new population projections must be provided by using 1985 population census data and other latest fertility and mortality information coflected by Korea Institute for Population and Health and Economic Planning Board in forth comming year.

• The Journal of Korean Physical Therapy
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• v.28 no.3
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• pp.217-220
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• 2016

Purpose: This study was to investigate the differences abdominal muscles activities of according to hip adductor contraction levels 20% (mild), 50% (moderate), and 70% (strong) of MVIC on during bilateral lower extremity raising exercise on supine. Methods: The subjects of the study were a total of 39 persons including 23 healthy males and 16 females, who performed bilateral lower extremity raising exercise in 20%, 50%, 70% MVIC hip contraction. Muscle activities were measured by using S-EMG in RA (rectus abdominis), IO (internal oblique), and EO (external oblique). Results: Muscle activity of the internal oblique abdominal muscle and external oblique abdominal muscle, their activities were also greatest with the adductor contraction size at 70% and there was statistically significant difference when compared with the adductor contraction size at 20% and 50% (p<0.05). As for the rectus abdominis muscle according to the size of contraction of the adductor was greatest at 70%, without statistically significant difference (p>0.05). Conclusion: bilateral lower extremity raising with strong hip joint adductor contraction was effective exercise to strengthen abdominal muscles. If subjects could not perform strong hip adductor contraction, moderate contraction is effective abdominal muscle contraction exercise. The contraction size of the adductor is small, weak contraction may trigger middle level contraction and therefore appropriate application of the exercise program of bilateral leg raising may result in great effect as a lumbar stabilization exercise.

• Journal of the Korean Wood Science and Technology
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• v.49 no.5
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• pp.482-490
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• 2021

This research was conducted to analyze the sound absorption effect of air-dried leaves from two evergreen tree species found in Korea's warm-temperate and subtropical regions. As eco-friendly sound absorption materials, Dendropanax morbiferusa, and Fatsia japonica leaves were prepared in three specimen units sizes 0.5 × 0.5 cm², 1.0 × 1.0 cm², and 2.0 × 2.0 cm², and each of them was formed at a thickness of 1.00 cm, 1.75 cm, and 2.50 cm. The measured sound absorption coefficients (SAC) for 18 conditions were comparatively analyzed in this study. The SAC of both tree species was significantly improved by increasing the dried leaf layer thickness. These results showed a more consistent and distinct trend for both tree species under the condition of 0.5 cm² in dried leaf size compared to other leaf specimen sizes. However, as the thickness increased, the difference in sound absorption effect according to the leaf size tends to decrease overall. In the case of D. morbiferus, there was no significant difference in SAC based on leaf size under the condition of 2.5 cm thickness (p < 0.05). The highest mean SAC was found in a 2.5 cm thick condition with a leaf size of 0.5 × 0.5 cm², 0.549 for D. morbiferusa, and 0.594 for F. japonica, respectively.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.201-212
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• 2021

This study attempted to compare the pattern with the absorption layer by analyzing the pattern of commercially available urinary incontinence panty products. Through this, it tried to obtain basic data necessary for the development of functional urinary incontinence panty for active seniors. Twelve commercially available products were decomposed to analyze size and patterns, and appearance and clothing pressure were evaluated through 3D simulation. As a result of comparing the size and pattern of urinary incontinence panty, it was analyzed that the size difference between parts was large even though the product was called the same. Products from the same brand also showed a big difference depending on design and absorption. As a result of the appearance evaluation for the 3D simulation, it was found that there were significant differences between products in all items such as the front, side, and back. Product No. 9 was analyzed to be the best except for the waist fit on the side. In the evaluation of clothing pressure, most of them were marked in red except for products 1, 2, and 8 due to the nature of the panty product. In the future, it is thought that actual wearing experiments and size standardization studies on urinary incontinence pants should be conducted.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.2
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• pp.23-32
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• 2004

The query optimizer's important task while a query is invoked is to estimate the fraction of records in the databases that satisfy the given query condition. The query result size estimation in spatial databases, like relational databases, proceeds to partition the whole input into a small number of subsets called “buckets” and then estimate the fraction of the input in the buckets. The accuracy of estimation is determined by the difference between the real data counts and approximations in the buckets, and is dependent on how to partition the buckets. Existing techniques for spatial databases are equi-area and equi-count techniques, which are respectively analogous in relation databases to equi-height histogram that divides the input value range into buckets of equal size and equi-depth histogram that is equal to the number of records within each bucket. In this paper we propose a new partitioning technique that determines buckets according to the maximal difference of area which is defined as the product of data ranges End frequencies of input. In this new technique we consider both data values and frequencies of input data simultaneously, and thus achieve substantial improvements in accuracy over existing approaches. We present a detailed experimental study of the accuracy of query result size estimation comparing the proposed technique and the existing techniques using synthetic as well as real-life datasets. Experiments confirm that our proposed techniques offer better accuracy in query result size estimation than the existing techniques for space query size, bucket number, data number and data size.

• Journal of Embryo Transfer
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• v.22 no.3
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• pp.191-194
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• 2007

The purpose of the present study was to set up basic information of size and status of ovaries by using ultrasonography to retrieve in vivo matured oocytes with ovum pick- up method. Ovaries were collected from the abattoir in Jeju in May and June which is breeding season. When the size of ovaries on ultrasonography was compared with real size measured by caliper, no significant difference was shown (p<0.05). The number of preovulatory follicles (>21mm) was investigated with ultrasonography and naked eyes. Ultrasonography group had 0.83 preovulatory follicles per ovary and naked-eye group had 0.75 preovulatory follicle per ovary and their average size was 2.86 cm and 2.34 cm, respectively. The average number of follicle was 4.25 with ultrasonography and 4.38 with naked eyes. There was no significant difference considering the size of follicle and number of follicle between ultrasonography and actual size except for the size of preovulatory follicle, suggesting that information of ultrasonography is able to use for OPU or other reproductive technology of mare.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1270-1276
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• 2005

When gas/particle partitioning of PAHs in the atmosphere approached an equilibrium state, the slope of linear regression between gas/particle partitioning coefficient($logK_p$) and subcooled liquid vapour pressure($logP_L^O$) was -1. But it was alleged that the slope of equilibrium state might not be -1 in real atmospheric environment due to heterogeneous characteristics of particulate matter. In This study, it would be found if gas/particle partitioning of PAHs segregated with particle size in equilibrium state was based on the hypothesis mentioned above. We have calculated the slopes of $logK_p$ v.s. $logP_L^O$ after collecting 10 set samples which consisted of particulate and vaporous phases. The slope was close to -1 in equilibrium states. But despite of equilibrium state, all slopes segregated with particle size were not close to -1 and those were gentler with larger particle size. The difference of slopes in equilibrium states was almost against the assumption of gas/particle partitioning theory. When the gas/particle partitioning was due to adsorption, the desorption enthalpy was different in each particle size. When it was absorption, the activity coefficient was different. The difference of desorption enthalpy and activity coefficient in each particle size indicate the heterogeneous characteristics of the bulk particle. This may be the reason for slope variation with particle size even though in an equilibrium state.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.2
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• pp.102-111
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• 2014

Purpose: Surface damage and bonding strength difference after micromechanical treatment of zirconia surface are to be studied yet. The aim of this study was to evaluate the difference of fracture resistance and bonding strength between more surface-damaged group from higher air-blasting particle size and pressure, and less damaged group. Materials and Methods: Disk shape zirconia ($LAVA^{TM}$) was sintered and air-blasted with $30{\mu}m$ particle size (Cojet), under 2.8 bar for 15 seconds, $110{\mu}m$ particle size (Rocatec), under 2.8 bar for 15 seconds, and $110{\mu}m$ particle size (Rocatec), under 3.8 bar for 30 seconds respectively. Biaxial flexure test and bonding failure load test were performed serially (n = 10 per group). For bonding test, specimens were bonded on the base material having similar modulus of elasticity of dentin with $200{\mu}m$-thick resin cement for tension of surface damage. Failure load of bonding was detected with acoustic emission (AE) sensor. Results: There were no significant differences both in the biaxial flexure test and bonding failure load test between groups (P > 0.05). Sub-surface cracks were all radial cracks except for two specimens. Conclusion: Within the limitations of no aging under monotonic load test, surface damage from higher air-blasting particle size and pressure was not significant. Evaluations of failure load with bonded zirconia disks was clinically relevant modality for surface damage and bonding strength, simultaneously.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.3_4
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• pp.390-401
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• 2002

This study was to evaluate the fitness and the suitability of size specification of the ready made jacket for women by analysing pattern size and space between skin and clothing using 3D scanner. The results were as follows: 1. Pattern B had the lowest score and the feeling of wearing was significantly different among the given patterns even though all jacket size specification were the same. 2. Ease amount was different between each brand even though the jacket size specification was the same due to the different pattern grading rules. And increasing grading amounts were bigger in horizontal direction rather than in vertical direction. 3. We could obtain accurate a 3 dimensional figure, using 3D scanner which was very useful and more accurate than 2 dimensional data using photography method. 4. Analyzing the average space between skin and clothing of each pattern, there was no significant difference in the average space between skin and clothing among all patterns except waist part of B88 size. And analyzing the average space between skin and clothing of each measured body parts by each size, there existed a significant difference in the interscye, abdomen and hip parts.

• Physical Therapy Rehabilitation Science
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• v.6 no.4
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• pp.170-175
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• 2017

Objective: The anti-inflammatory effects of low-level laser in burn wound model in rats were investigated. Design: Randomized controlled trial. Methods: The rats were assigned to three experimental groups. Group I received second-degree burn wounds; Group II received dressing film and low-level laser ($1.2J/cm^2$) treatment after a burn wound; Group III received dressing film and low-level laser ($2.3J/cm^2$) treatment after a burn wound. After inducing a deep second-degree burn wound, the wound was observed every day and the burn area diameter and retraction quantification at 1, 7, and 14 days were evaluated. Low-level laser was investigated on hematological parameters after 14 days. Effects of low-level laser on the inflammatory cytokines (tumor necrosis $factor-{\alpha}$ [$TNF-{\alpha}$] and interleukin-6 [IL-6]) concentrations in the serum were evaluated using immunosorbent assay kits. Results: Group III showed a significant difference in wound size on days 7 and 14 compared to Group I (p<0.05). Group II showed a significant difference in wound size on day 14 compared to Group I (p<0.05). For wound contraction percentage, both laser therapy treatment groups showed a significant difference compared with Group I (p<0.05). There was also a significant difference in wound contraction percentage in Group III compared to Group II (p<0.05). Compared with the model control group, decreased $TNF-{\alpha}$ and IL-6 levels in the serum was observed at 14 days after burn wound induction. Conclusions: The results of this study suggest that low-level laser therapy can assist in burn wound healing, which might be associated with decreased concentrations of $TNF-{\alpha}$ and IL-6 related proinflammatory cytokines.