• Journal of the korean academy of Pediatric Dentistry
• /
• v.35 no.4
• /
• pp.635-641
• /
• 2008

The purpose of study was to investigate the etiologic factors of maxillary primary anterior caries. The subjects of study were 401 preschool children, 214 boys and 187 girls, from 36 to 71 months old of randomly selected seven nurseries in Iksan city. The prevalence of maxillary primary anterior teeth was cross-analyzed with gender, age, breast feeding or bottle feeding, length of feeding, sweet snack intake frequency, beginning of toothbrushing, and toothbrushing frequency per day. The prevalence was 43.0% in boys and 26.7% in girls, and there was significant association between the prevalence and gender in cross analysis(P<0.01). The prevalences of the shorter than 2 years of feeding group, the from 2 to 3 years group, and the longer than 3 years group were 31.0%, 43.2%, and 63.2%, respectively, and there was significant association between the prevalence and the length of feeding(P<0.01). Daily intake of sweet snacks had a significant association with the prevalence(P<0.05). There was no significant association between the prevalence and the variables of age, breast feeding or bottle feeding, beginning of toothbrushing, and toothbrushing frequency per day(P>0.05).

• Korean Journal of Poultry Science
• /
• v.15 no.2
• /
• pp.73-79
• /
• 1988

In order to study the effects of feeding time (08：00 and 14：00 hours) and frequency (once a day, twice a day and once every other day) on the performances of broiler breeder hens, two experiments were conducted with 1, 248 hens of Maniker strain during 24－2 weeks (Experiment 1) and 42－60 weeks (Experiment 2) of age. The results obtained are summarized as follows ： 1. No significant differences were observed in hen－day egg production and feed conversion rate between feeding times or among feeding frequencies through the entire experimental period. 2. Mean egg weight during the age of 24－42 weeks was significantly increased by feeding in the afternoon (p＜0.01). But it was not significantly affected by feeding time or frequency during 42－60 weeks of age. 3. Fertility and hatchability of eggs at 36 weeks and 60 weeks of age were not significantly different among treatments. 4. By feeding in the afternoon egg breaking strength at 60 weeks of age was significantly improved (p＜0.05), but not at 36 weeks of age. 5. In diurnal distribution of egg production, hens fed in the afternoon produced more eggs in the afternoon than hens fed during the morning (p＜0.01).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.9 no.4
• /
• pp.515-525
• /
• 1998

In this paper, for both transmission and reception with single antenna system of satellite communication, dual-frequency antennas which operate simultaneously at 12.5 GHz and at 14.25 GHz are designed, constructed and measured. Also by using dual feeding structure, the problems of single-fed dual-frequency antenna such as the separation of transmitting and receiving signals and single polarization, are solved. Microstrip patch as a radiation element of dual-fed dual-frequency antenna has width and length which are the resonance lengths of the corresponding frequencies for transmission and reception, respectively. The effects of the feed line on the other frequency feeding are minimized with the optimal matching scheme for the feed lines. For solving the space problems of dual-fed two-dimensional array antennas, microstrip-line and coaxial probe feedings are used for each frequency and a two-dimensional $2\times2$ array antenna was designed and measured their characteristics. The experimental results show that errors of resonance frequencies are less than 1.44%, the return losses are less than -21 dB and the isolations between two feeding ports are less than -21 dB. The characteristics of radiation patterns of dual frequency microstrip antenna are measured and evaluated. The directivities, sidelobe levels and cross polarizations are also measured and compared with the simulations. The results show some errors due to the misalignment of coaxial probe feeding.

• Nutrition Research and Practice
• /
• v.12 no.6
• /
• pp.512-520
• /
• 2018

BACKGROUND/OBJECTIVES: The 6-23 months for infants is the longest period in the "first 1,000 days" of life. This period is very important for child development, so complementary feeding (CF) practices should be optimized to maximize children's potential for growth and development. The aim of this study was to analyze the CF practices and nutritional status of children aged 6-23 months. SUBJECTS/METHODS: For this cross-sectional study, 392 children aged 6-23 months were selected using stratified random sampling. Socio-demographic data were collected through interviews. CF practices, collected by interviews and repeated 24-hour food recall method, were the timely introduction of CF, minimum meal frequency, dietary diversity and minimum acceptable diet, consumption food rich in proteins and vitamin A. Nutritional status was assessed using the indicators of underweight, wasting and stunting. To analyze the association between socio-demographic indicators and CF with nutritional status, the chi-square test with a confidence interval of 95% was used. RESULTS: Results showed that 39% were exclusively breastfed, only 61% received prolonged breastfeeding and 50% received timely introduction of CF. Minimum meal frequency was met by 74% of subjects, but dietary diversity and minimum acceptable diet were only realized in 50% and 40% of the children, respectively. The prevalence of underweight, wasting, and stunting were 26%, 23%, and 28%, respectively. Age of the child, birth order, birth weight, parents' education level, family size and incidence of fever and diarrhea during the previous two weeks were associated with underweight, while child's birth order, fathers' education level, mother's age, family size, completion of the age-appropriate vaccination and fish consumption frequency were associated with wasting. Age of the child, incidence of fever and acute respiratory infection, and fortified food consumption were associated with stunting. CONCLUSIONS: Suboptimal CF practices and high prevalence of underweight, wasting and stunting were found among children aged 6-23 months old in Aceh. These results highlight the need to improve CF and nutritional status.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.1
• /
• pp.72-81
• /
• 2009

Eight Black Belly rams (45.2 kg) fitted with permanent ruminal cannulae were used in a 2${\times}$2 factorial design to determine the effects of feeding frequency and regrowth age on intake and digestion. Rams were fed with 21- or 35-day old fresh pangola grass offered ad libitum two or four times a day. Irrespective of the regrowth age, there was a tendency for intake to be positively correlated with increase in meal frequency. Differences were not significant (p>0.25). Significant effects of meal frequency were observed in NDF and ADF total tract digestibility of the 35-day grass which decreased as the number of meals increased. Meal frequency had no visible effect on feeding behaviour. Total rumen content increased when animals were fed twice a day as opposed to four times a day. Similarly, an accumulation of small and very small particles was observed in the rumen of rams fed twice a day in comparison with those fed four times a day. These results suggest that studies of digestive dynamics performed at a steady state are not representative of the rumen loading observed in farm rams which have two important peaks of meal.

• Asian-Australasian Journal of Animal Sciences
• /
• v.4 no.1
• /
• pp.79-83
• /
• 1991

Diurnal variation in faecal chromic oxide levels was estimated from 4 hourly faecal sampling of 56 wethers allotted to one of six different feeding patterns. Sampling occurred on days 6 and 7 (Period 1) after a controlled release device was administered, and was repeated on days 14 and 15 (Period 2) following re-randomisation of the wethers to the feeding patterns. Increasing the frequency of feeding tended to be associated with higher faecal chromic oxide levels (p < 0.05), particularly in wethers fed thrice daily at 8 hour intervals. There was no interaction between feeding pattern and period, sampling day or time within-day. There were significant period x time within-day (p < 0.05) and day x time within-day (p < 0.001) interactions, indicating that variation in faecal chromic oxide between sample times was not consistent. This implies that sampling at any time of day is unlikely to result in a biased estimate of pasture intake, providing sufficient samples are collected. Significant period (p < 0.001) and period x day (p < 0.01) effects were associated with slow faecal chromic oxide equilibration in period 1. Equilibration did not occur until after day 7, indicating a need for caution when commencing sampling.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11b
• /
• pp.92-97
• /
• 2002

There are a lot of roots of errors in an motion of the optical pick-up actuator being one of the most significant components in a CD-ROM drive. Most of the studies recently performed have a tendency to seek for the causes from an actuator itself. This paper present the dynamic characteristics of an actuator affected by the motion of a feeding deck. The feeding system is modeled as a rigid body with eight degree-of-freedom. Using Largrange's equation, we derive the linear equations of motion with respect to the rectangular coordinate. We found the fact that the ranges of the natural frequencies of a feeding deck and an actuator are close to each other. And the time responses are also computed by the Newmark method and Runge-Kutta method.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2002.11a
• /
• pp.285-289
• /
• 2002

In this paper, microstrip line-probe feeding patch array antenna with center frequency 5.8㎓ is designed and manufactured. The microstrip line - probe feeding structure has broadband characteristic and be able to modify the array structure for improving antenna gain. In this result, microstrip line-probe feeding patch array antenna has 17.6% bandwidth and 8㏈i antenna gain, respectively.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.50 no.6
• /
• pp.257-262
• /
• 2001

In this paper, a linear ultrasonic motor using piezoelectric ceramics was fabricated, and its operation characteristics were investigated. A linear ultrasonic motor using L$_1$-B$_4$model was composed of a stator and a rotor, and a stator was composed of piezoelectric ceramics and a elastic body. When applied frequency and voltage were 58.4kHz and 56V respectively, the feeding speed of the motor was 19.8 cm/s. A linear ultrasonic motor could be moved in left and right directions by the phase difference. Feeding speed and feeding force of a linear ultrasonic motor could be controlled by applied voltage. A linear ultrasonic motor had a droping torque-speed characteristic. The maximum efficiency of linear ultrasonic motor was 2.14%. Therefore, this linear ultrasonic motor can be expected to be used for a card-forwarding device, such as a card reader device and so on.

• Clinical and Experimental Pediatrics
• /
• v.51 no.8
• /
• pp.820-826
• /
• 2008

Purpose : This study was conducted to evaluate the red cell indices and frequency of iron deficiency anemia based on the feeding patterns of nine-month-old infants. Methods : Blood tests were performed on 253 nine-month-old infants, who visited Il Sin Christian Hospital for health check-ups from January to December 2007. Their parents answered telephonic questions regarding their feeding patterns and weaning foods. Results : Three infants groups were created according to feeding patterns before they started weaning foods. One group was exclusively breast-fed (48.6%), another had mixed feeding (27.3%), and the third had artificial milk feeding (24.1%). Red cell indices (hemoglobin, hematocrit, MCV, MCH) of the breast-fed group were comparatively lower than those of the other two groups (P<0.05). Twenty-five infants (9.9%) were diagnosed with iron-deficiency anemia. According to feeding patterns, the frequency of anemia was highest in the breast-fed group. Six infants who started weaning foods before six months of age (113 infants) were diagnosed with iron-deficiency anemia (5.3%), and nineteen who started after six months of age (140 infants) were diagnosed with iron-deficiency anemia (13.6%). Conclusion : When nine-month old infants visit hospitals for health check-ups, pediatricians must consider their feeding pattern and weaning foods histories, and then recommend screening blood tests for iron-deficiency anemia.