• Journal of the East Asian Society of Dietary Life
• /
• v.14 no.2
• /
• pp.113-122
• /
• 2004

This study was conducted to examine the correlation among growth development, bone mineral density, and nutrient intakes in preschool children. A total of 62 preschool children measured the anthropometric characteristics and the bone mineral density of carpus using DEXA. The questionnaires categorized to determine health status, life style, dietary behaviors, and dietary intakes were filled out by children's mothers. The average ages of the study subjects were 62.4 months in boys and 62.1 months in girls. The birth height and weight of the subjects were 50.9 cm and 3.4 kg in boys and 50.3 cm and 3.3 kg in girls, respectively. The average height, weight, % body fat, and obesity index were 111.7 cm, 19.6 kg, 15.0%, -2.1% in boys and 109.4 cm, 18.7 kg, 17.5%, 0.2% in girls, respectively. The bone mineral density in carpus was 0.25 g/cm$^2$ in boys and 0.24 g/cm$^2$. In girls. Proportions of children having regular meals were 69.0%, 94.7%, and 69.0% for breakfast, lunch, and dinner, respectively. The major reasons for irregular meal were poor appetite and lack of time for breakfast and snacks for dinner. Most of the children(52.6%) had breakfast with the whole family together, and all the children had lunch and dinner with a part of the family. Most of the children answered they had snack more than once a day, and 64.3% had an unbalanced diet. The intakes of energy, calcium, iron, zinc, vitamin A, vitamin B$_1$, niacin, and vitamin C did not meet the Korean RDAs. Average bone mineral density in carpus was positively correlated to the body weight, the total body water, the lean body mass, and the obesity index, respectively(p＜0.01, p＜0.01, p＜0.01 and p＜0.01). The body weight, the total body water, and the lean body mass showed the significant negative correlations with the animal iron intake(p＜0.05, p＜0.01 and p＜0.01). The bone mineral density in the distal carpus was negatively correlated to the animal protein intake and the animal iron intake(p＜0.05 and p＜0.05). And the bone mineral density in the ultradis carpus and the average bone mineral density in the carpus were positively correlated to the plant calcium intake(p＜0.05 and p＜0.05). Therefore, more systematic studies to investigate the roles of protein, iron, and calcium in growth development of preschool children were required.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.6
• /
• pp.847-852
• /
• 2014

The aim of this study was to investigate the effects of stocking density and water temperature in the rearing of the longtooth grouper Epinephelus bruneus. Juvenile fish [mean body weight (BW)=$6.9{\pm}1.1g$] were raised for 6 weeks, in four density groups of 0.25, 0.5, 0.75, and 1 individuals/L. There were no significant differences in weight gain (WG) or specific growth rate (SGR) among the density groups; however, both WG and SGR tended to be higher in the low density group. After 6 weeks of rearing in temperature-controlled water ($23.6{\pm}0.8^{\circ}C$) and ambient temperature water ($19.6{\pm}1.8^{\circ}C$), there were no significant differences in WG or SGR values, but both tended to be higher in the temperature controlled water. The feed efficiency (FE) and daily feed intake (DFI) and WG values were also higher in the temperature-controlled water than in the ambient temperature water. WG values were lower at lower water temperatures. The same pattern was observed for SGR, FE, and FI, all of which exhibited lower values at lower temperatures. In particular, WG, SGR, and FE values all tended to decrease at the $16^{\circ}C$ water temperature. The effects of water temperature on 1-year fish (mean BW = $387.6{\pm}30.2g$) and 3-year fish (mean BW = $1,338.3{\pm}73.8g$) were similar to those of the juvenile fish (0-year fish).

• The Korean Journal of Malacology
• /
• v.26 no.4
• /
• pp.297-302
• /
• 2010

Water temperature, salinity and density on egg development of the sunray surf clam, Mactra chinensis were investigated for artificial seedling production. The required time from fertilization to D-shaped larvae were 33.8 hours in $18^{\circ}C$, 20.6 hours in $23^{\circ}C$, 18.2 hours in $28^{\circ}C$ and 15.0 hours in $33^{\circ}C$. The development duration was reduced with increasing temperature. The relationships between temperature and the required time from egg to each developmental stage were described as follows: 2-cell, 1/h = 0.1051WT - 1.4782; 8-cell, 1/h = 0.037WT - 0.3686; gastrula, 1/h = 0.008WT - 0.0521; trochophore, 1/h = 0.0041WT - 0.0235; D-shaped larva, 1/h = 0.0024WT - 0.0102. Biological minimum temperature for the egg development was estimated to be $8.0^{\circ}C$ in average. The possible range of temperature for the development of D-shaped larvae was $18-28^{\circ}C$ and optimum of water temperature for the development of egg was $23^{\circ}C$. The possible range of salinity for the development of D-shaped larvae was 20-35 psu and optimum of salinity for the development of egg was 30-35 psu over 25 psu at least. The density of fertilized egg was below 40 per 1 ml in rearing seawater for elevating the development rate from fertilized egg to D-shaped larva.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.1
• /
• pp.44-53
• /
• 2009

The Purpose of this study is to find out necessity and possibility of low-rise high density housing improving an old residential district of hillside areas. Housing of hillside areas should be maintained and it is necessary to make topographical adaptation plan. For this purpose, we calculate the floor area ratio to break even on case study area by GIS date. As a result, we found out that floor area ratio as minimum qualifications for the feasibility of urban redevelopment is 180%, and carried out a landscape simulation to a low-rise high density housing by AutoCAD 2004 and ArcView 3.2a. In results of simulations, it reveals that a rule to low-rise high density housing effective for topographical adaptation development.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.469-474
• /
• 2005

Tn this study, the noll-destructive computed X-ray tomography was adopted to observe the density distribution of the needle-punched C-C composites nozzle throat. The density distribution of the C-C was evaluated within ${\pm}0.01g/cm^3$ with 98.74% confidence when the correction of the image and high signal-to-noise ratio were achieved by the optimization of the beam hardening, the electrical noise and the scattered X-ray. The density variation of the C/C with the computed tomography was in good agreement with the results obtained by the water immersion method and the observation with scanning electron microscope.

• Journal of Ecology and Environment
• /
• v.44 no.4
• /
• pp.241-255
• /
• 2020

Background: The stem exclusion stage is a stage of forest development that is important for understanding the subsequent understory reinitiation stage and maturation stage during which horizontal heterogeneity is formed. Over the past 11 years (2009-2019), we observed a deciduous broad-leaved forest in the Albongbunji Basin in Ulleungdo, South Korea in its stem exclusion stage, where Fagus engleriana (Engler's beech) is the dominant species, thereby analyzing the changes in the structure (density and size distributions), function (biomass and species richness), and demographics. Results: The mean stem density data presented a bell-shaped curve with initially increasing, peaking, and subsequently decreasing trends in stem density over time, and the mean biomass data showed a sigmoidal pattern indicating that the rate of biomass accumulation slowed over time. Changes in the density and biomass of Fagus engleriana showed a similar trend to the changes in density and biomass at the community level, which is indicative of the strong influence of this species on the changing patterns of forest structure and function. Around 2015, a shift between recruitment and mortality rates was observed. Deterministic processes were the predominant cause of tree mortality in our study; however, soil deposition that began in 2017 in some of the quadrats resulted in an increase in the contribution of stochastic processes (15% in 2019) to tree mortality. The development of horizontal heterogeneity was observed in forest gaps. Conclusions: Our observations showed a dramatic shift between the recruitment and mortality rates in the stem exclusion stage, and that disturbance increases the uncertainty in forest development increases. The minor changes in species composition are likely linked to regional species pool and the limited role of the life-history strategy of species such as shade tolerance and habitat affinity. Our midterm records of ecological succession exhibited detailed demographic dynamics and contributed to the improvement of an ecological perspective in the stem exclusion stage.

• Korean Journal of Remote Sensing
• /
• v.28 no.3
• /
• pp.297-305
• /
• 2012

This study was performed to estimate forest canopy density (FCD) using airborne hyperspectral data acquired in the Independence Hall of Korea in central Korea. The airborne hyperspectral data were obtained with 36 narrow spectrum ranges of visible (Red, Green, and Blue) and near infrared spectrum (NIR) scope. The FCD mapping model developed by the International Tropical Timber Organization (ITTO) uses vegetation index (VI), bare soil index (BI), shadow index (SI), and temperature index (TI) for estimating FCD. Vegetation density (VD) was calculated through the integration of VI and BI, and scaled shadow index (SSI) was extracted from SI after the detection of black soil by TI. Finally, the FCD was estimated with VD and SSI. For the estimation of FCD in this study, VI and SI were extracted from hyperspectral data. But BI and TI were not available from hyperspectral data. Hyperspectral data makes the numerous combination of each band for calculating VI and SI. Therefore, the principal component analysis (PCA) was performed to find which band combinations are explanatory. This study showed that forest canopy density can be efficiently estimated with the help of airborne hyperspectral data. Our result showed that most forest area had 60 ~ 80% canopy density. On the other hand, there was little area of 10 ~ 20% canopy density forest.

• Journal of the Korea Furniture Society
• /
• v.10 no.1
• /
• pp.95-102
• /
• 1999

The objective of this paper was the development of boards made from waste newspapers. The boards were produced from particle ONP(old newspaper) to reduce energy consumption in the board production process. ONP boards bonded with polyurethan adhesives(PU) were produced on a laboratory scale, and their physical and mechanical properties were examined. The average density of the ONP was $0.48g/cm^3$, and the densities of the boards were $0.50-0.90g/cm^3$. Therefore, th compaction ratios of the boards were in the range of 1.04-1.88. The results obtained were as follows: 1) An increase in board density results in a corresponding improvement in bending properties. 2) An increase in board density results in increased thermal conductivity. 3) In this research, ONP board can be used only for interior applications. To gain exrerior applications, the dimensional stability properties(thickness swelling and water absorption) need to be improved.

• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.307-309
• /
• 2000

This paper presents development of program for mid-tong term load forecasting in region and district respectively. In this program, at first, the region is classified by KEPCO branch which can be analyzed in light of curl·elation between load characteristics and economic indicator and then, prediction for load density in each region was performed by scenario of economic, population and city plan. Secondly, prediction for load density in each district is performed by methodology which is based on land use method. Finally efficiency for prediction work in each KEPCO branch could be identified by applying the developed program to the Seoul city in real.

• Journal of Korean Society of Transportation
• /
• v.29 no.3
• /
• pp.83-91
• /
• 2011

This paper discusses models for estimating dynamic travel times based on probability theory. The dynamic travel time models proposed in the paper are formulated assuming that the travel time of a vehicle depends on the distribution of the traffic stream condition with respect to the location along a road when the subject vehicle enters the starting point of a travel distance or with respect to the time at the starting point of a travel distance. The models also assume that the dynamic traffic flow can be represented as an exponential distribution function among other types of probability density functions.