• 한국해양학회지
• /
• v.13 no.1
• /
• pp.1-8
• /
• 1978

A seismic reflection Survey was carried out in the offshere area between Geoje Island and Namhae Island, utilizing the echosounder with the frequency 28KHz and thd Uniboom with the filter band 800∼2000Hz. The results show the submarine topography, sedimentary layer structure and the depth distribution of the base rock. The water depth of the sea in the survey area is less than 80m; up to 40m contour line the sea bottom surface has a slight dip(about 1/1000), while in the zone deeper than 40m the bottom topography has a irregular relief. The thickness of the whole sedimentary deposit is about 20∼70m and divided into 3 layers: Upper layer(A layer) with horizontal laminae, intermediate layer(B layer) with cross-bedding and groove structure, and lower layer(C layer) not showing any sedimentary structure on the seismic reflection profile. The surface of the base rock is deeper gradually in the south-eastern part of the survey area and extends to 140m depth. The vertical sediments sequences, composed of B layer and A layer, show the type of transgressive sequences. It is interpreted that B layer was formed at one period when the sea level was lower 40∼60 than the present and ince then, following the rising of the sea level, A layer was deposited.

• Korean Journal of Community Nutrition
• /
• v.2 no.4
• /
• pp.486-495
• /
• 1997

The purpose of this study was to determine the prevalence of obesity and to examine the eating habits of elementary school students in Kwangju. The study was carried out on 931 students(male : 454, female : 477) in September and October of 1996. The results are summarized as follows ; Obesity was defined as body mass index(BMI) that exceeds 20. The rate of obesity was 10.0%(male 4.7$\%$, female 5.3$\%$) in subjects. Subjects were divided into 3 groups : normal group(BMI〈20), mildly obese group(20〈BMI〈25), and moderatly obese group(25〈BMI〈30), respectively. With regard to frequency of skipping breakfast, 9.1$\%$ of normal children and 17.5$\%$ of mildly obese children and 33.3$\%$ of moderately obese children had skipping every morning(p$\ll$0.001). With regard to the regularity of meal time, 62.1$\%$ of normal children had ‘regular meals’but 58.0$\%$ of mild obese children and 50.0$\%$ of moderate obese children had‘irregular meals’(p$\ll$0.05). With regard to meal volume, obese children consumed much more meal volume than normal children(breakfast p$\ll$0.001, lunch p〈0.005, dinner p$\ll$0.001). With regard to try to lose weight, 22.9$\%$ of normal children and 55.6$\%$ of mild obese children and 83.3$\%$ of moderated obese children indicated they had attempted(p$\ll$0.001). The results of this study showed that the prevalence of obesity in elementary school students in Kwangju has a tendency to be increased. Obese children need to correct their eating habits. This reasserts the importance of nutrition education in children through teachers, parents and dietitians. The findings of this study should be applied to nutrition education to ensure better physical fitness of children. (Korean J Community Nutrition 2(4) : 486-495, 1997)

• The Korean Journal of Food And Nutrition
• /
• v.11 no.2
• /
• pp.165-170
• /
• 1998

Diagnostic radiology and conservative management for S75 patient with L1 lumbar fracture by traffic accidents were discussed with references, and then the obtained results were as follows ; 1. Wedging compression fractures with 10% deformity was confirmed at anterior vertebral body of L1 lumbar spine through lateral plain X-ray film. 2. Irregular bony fractures were observed at anterior vertebral body of L1 lumbar spine by CT scans, anatomically T12-L1 sites showed highly frequency of injuries, Denis's fracture type was classified as multiple compression fracture at anterior column without abnormal middle and posterior column, also no Cobb's angle, and then Frankel's neurological classification was E grade. 3. Orthopaedic treatments were performed with conservative methods. With rest on the bed, anti-in-flammatory medication, electrolyte and nutritional solution, the pain diminished. 4. After 3 weeks, rehabilitation was worked with putting on polyethylene back corset, although pains remained slightly until after 8 weeks, thereafter the spine showed gradually stability.

• The Korean Journal of Food And Nutrition
• /
• v.23 no.3
• /
• pp.342-351
• /
• 2010

This study was conducted to investigate the dietary behavior of day-care center teachers and their meal attitudes during meal time in Jeonju area. Self administered questionnaires were collected from 266 day-care center teachers who worked in a national(public) or private day-care center. The Statistical data analysis was conducted using SPSS v. 12.0. All subjects were women, and 64.7% were married(p<0.001), over more than 60% were junior college graduates(p<0.05), and 73.7% had salaries greater than 1,000,000 won(p<0.001). The breakfast skipping ratio of the subjects was very high, and about 66.5% of the respondents had irregular meals. The snack intake ratios of the subjects in private day-care centers were higher than the subjects in national(public) day-care centers(p<0.001). Approximately 56% of the subjects responded that education about eating is very important for providing balanced nutrition to young children. About 84% of subjects had no experience with the continuing-education program for teachers(p<0.01), and they wanted to know more about balanced nutrition. The meal attitude education score during meal time was $4.53{\pm}0.36$. The relationship between meal attitude education and the dietary behavior of day-care teachers was significantly different based on the "frequency of overeating"(p<0.05) and "self-recognition of eating habit"(p<0.05). These findings suggest that a nutrition education program for day-care center teachers should be developed so that they can effectively manage meal attitude education for young children and provide good nutrition for themselves.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.9
• /
• pp.1115-1124
• /
• 1988

A two-dimensional systolic array for fast Fourier transform, which has a regular and recursive VLSI architecture is presented. The array is constructed with identical processing elements (PE) in mesh type, and due to its modularity, it can be expanded to an arbitrary size. A processing element consists of two data routing units, a butterfly arithmetic unit and a simple control unit. The array computes FFT through three procedures` I/O pipelining, data shuffling and butterfly arithmetic. By utilizing parallelism, pipelining and local communication geometry during data movement, the two-dimensional systolic array eliminates global and irregular commutation problems, which have been a limiting factor in VLSI implementation of FFT processor. The systolic array executes a half butterfly arithmetic based on a distributed arithmetic that can carry out multiplication with only adders. Also, the systolic array provides 100% PE activity, i.e., none of the PEs are idle at any time. A chip for half butterfly arithmetic, which consists of two BLC adders and registers, has been fabricated using a 3-um single metal P-well CMOS technology. With the half butterfly arithmetic execution time of about 500 ns which has been obtained b critical path delay simulation, totla FFT execution time for 1024 points is estimated about 16.6 us at clock frequency of 20MHz. A one-PE chip expnsible to anly size of array is being fabricated using a 2-um, double metal, P-well CMOS process. The chip was layouted using standard cell library and macrocell of BLC adder with the aid of auto-routing software. It consists of around 6000 transistors and 68 I/O pads on 3.4x2.8mm\ulcornerarea. A built-i self-testing circuit, BILBO (Built-In Logic Block Observation), was employed at the expense of 3% hardware overhead.

• Proceedings of the Korean Biophysical Society Conference
• /
• 2003.06a
• /
• pp.38-38
• /
• 2003

The electrical properties of neurons are produced by the coordinated activity of ion channels (Hille, 1992). $K^{+}$ channels play a key role in shaping action potentials and in determining neural firing patterns. Small conductance $Ca^{2+}$-activated $K^{+}$ (S $K_{Ca}$ ) channels are involved in modulating the slow component of afterhyperpolarization (AHP) (Kohler et al., 1996). Here we examine whether rat type 2 S $K_{Ca}$ (rSK2) channels can affect the shape of the action potential and the neural firing pattern, by overexpressing rat SK2 channels in Aplysia neuron R15. Our results show that rSK2 overexpression decreased the intraburst frequency and changed the regular bursting activity of neurons to an irregular bursting or beating pattern in R15, Furthermore, the overexpression of rSK2 channels increased AHP and reduced the duration of the action potential. Thus, our results suggest that ectopic S $K_{Ca}$ channels play an important role in regulating the filing pattern and the shape of the action potential.ntial.

• Journal of the Korean Geophysical Society
• /
• v.3 no.2
• /
• pp.91-98
• /
• 2000

The seismicity of the Korean Peninsula shows a very irregular pattern of strain release typical of the intraplate seismicity. The Korean Peninsula may be divided into several tectonic provinces of differing tectonics. In this analysis, seismicity parameters for each tectonic province are evaluated from historical as well as instrumental earthquake data of the Korean Peninsula to examine the differences in seismic characteristics among tectonic provinces. Statistical analysis of the earthquake data made of incomplete data before the Choseon Dynasty and complete data afterwards reveals that there exist no significant differences in seismic characteristics between the tectonic provinces. It turns out the b-value in the intensity-frequency relation for the whole peninsula is about 0.6 and the maximum earthquake is about MMI X. The results of this study may be used in the probabilistic seismic hazard analysis of the Korean Peninsula and in estimating the design earthquake in earthquake engineering.

• Ocean Systems Engineering
• /
• v.10 no.1
• /
• pp.87-110
• /
• 2020

Catamaran has recently been a choice to support a typical vertical axis turbine in floating tidal current energy conversion system. However, motion responses associated with the catamaran can reduce the turbines efficiency. The possibility to overcome this problem isto change the catamaran parameter by varying and simulating the demi-hull separations to have lower motion responses. This simulation was undertaken by Computational Fluid Dynamic (CFD) using potential flow analysis. Cases of demi-hull separation were considered, with ratios of demi-hull separation (S) to the breadth of demi-hull (B), ^S/_B of 3.45, 4.95, 6.45, 7.2 and 7.95. In order to compare to the previous works in the literature, the regular wave was set with wave height of 0.8 m. Furthermore, the analysis was carried out by irregular waves with significant wave height, H_s, of about 0.09 to 1.5 m and the wave period, T, of about 1.5 to 6 s or corresponding to the wave frequency, ω, of about 1.1 to 4.2 rad/s. The wave spectrum was derived from the equation of the International Towing Tank Conference (ITTC). For the case of turbines-loaded catamaran under consideration, the new finding is that the least significant amplitude response can be satisfied at the ratio ^S/_B of 7.2. This study indicates that selecting a right choice of demi-hull separation ratio could contribute in reducing motion responses of the tidal current turbines-loaded catamaran.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.2
• /
• pp.361-382
• /
• 1997

The effect of fluoride pretreatment upon root resorption after delayed replantation was studied in beagle dogs. Upper and lower incisors were extracted and bench dried for 45 minutes. 1% Stannous fluoride solution, 2% neutral sodium fluoride gel and 1.23% acidulated phosphate fluoride gel were used for the pre-treatment of replanted root surface in the experimental groups. Replantation was done with no treatment in control group. After of an experimental periods 3 weeks, animals were sacrificed by perfusion followed by sample preparation. A histomorphometric method was applied for evaluation of tissue reactions observed in each group under light microscope. Scanning electron microscopic observation was done to find out any different surface topography between groups. The results were as follows: 1. Fluoride-treated groups showed in general the better healing patterns than untreated control group. 2. Comparisons between three experimental groups revealed the general superiority of APF-treated group over the other groups in terms of tissue healing reaction by showing the highest frequency in uncomplicated healing pattern and surface resorption and the lowest in inflammatory resorption, but with no statistical significance(p>.05). 3. Scanning elecron micrographs showed the irregular distribution of resorption cavities and the attached bone of variable size and shape in all groups. 4. It can be concluded that the types of fluoride did not have significant impact on the early tissue reactions after delayed replantation under the condition of the present experiment.

• Smart Structures and Systems
• /
• v.12 no.3_4
• /
• pp.251-269
• /
• 2013

Measurement of deflections of certain bridges is usually hampered by corruption of the GPS signal by multipath associated with passing vehicles, resulting to unrealistically large apparent displacements. Field data from the Gorgopotamos train bridge in Greece and systematic experiments revealed that such bias is due to superimposition of two major effects, (i) changes in the geometry of satellites because of partial masking of certain satellites by the passing vehicles (this effect can be faced with solutions excluding satellites that get temporarily blocked by passing vehicles) and (ii) dynamic multipath caused from reflection of satellite signals on the passing trains, a high frequency multipath effect, different from the static multipath. Dynamic multipath seems to have rather irregular amplitude, depending on the geometry of measured satellites, but a typical pattern, mainly consisting of a baseline offset, wide base peaks correlating with the sequence of main reflective surfaces of the vehicles passing next to the antenna. In cases of limited corruption of GPS signal by dynamic multipath, corresponding to scale distortion of the short-period component of the GPS waveforms, we propose an algorithm which permits to reconstruct the waveform of bridge deflections using a weak fusion of GPS and RTS data, based on the complementary characteristics of the two instruments. By application of the proposed algorithm we managed to extract semi-static and dynamic displacements and oscillation frequencies of a historical railway bridge under train loading by using noisy GPS and RTS recordings. The combination of GPS and RTS is possible because these two sensors can be fully collocated and have complementary characteristics, with RTS and GPS focusing on the long- and short-period characteristics of the displacement, respectively.