• Proceedings of the KIEE Conference
• /
• 2000.07d
• /
• pp.3207-3209
• /
• 2000

X-ray CT(Computed Tomography) has been a good modality for non-invasive diagnosis and recently, Conventional CT has been replaced rapidly with Spiral CT in recent. In X-ray CT, spiral scanning has various advantages such as better image quality, reduced scan time (in a single breath-hold), a lower x-ray dose. But, it requires very fast and high performance image processing system to reconstruct slice images from spiral scanning. This paper describes the fast image reconstruction techniques with filtered back projection from the viewpoints of fast algorithm as well as hardware implementation for real-time imaging.

• The Journal of Korean Academy of Prosthodontics
• /
• v.52 no.2
• /
• pp.105-112
• /
• 2014

Purpose: The aim of present investigation was to find out the influence of several times iatrogenic mobilization in the initial stage of implant installation on bone-implant osteointegration. Materials and methods: The experimental implants (3.75 mm in diameter, 8.0 mm in length) were made of commercially pure (Grade IV) titanium, and were treated with RBM ($MegaGen^{(R)}$: Ca-P) on lower 4.0 mm part. Only lower part of implant was inserted to bone and the implants were nonsubmerged. The 130 implants (two in each tibia) were inserted into the monocortical tibias of 33 rabbits which each weighed more than 3.5 kg (Female, New Zealand White). According to the removal torque interval, the groups were divided into 13 groups, group I (1 day), group II (1 day + 2 days), group III (1 day + 2 days + 3 days), group IV (1 day + 2 days + 3 days + 4 days), group V (2 days), group VI (2 days + 4 days), group VII (2 days + 4 days + 6 days), group VIII (2 days + 4 days + 6 days + 8 days), group IX (4 days), group X (4 days + 7 days), group XI (4 days + 7 days + 10 days), group XII (4 days + 7 days + 10 days + 14 days) and control group. In the control group, the removal torque was measured at 8 weeks with a digital torque gauge (Mark-10, USA). In the experimental groups, the removal torque was given once, twice, three times or four times by experiment design before the final removal torque and the value was measured each time. The implants were then screwed back to their original positions. All the experimental groups were given a final healing time of 8 weeks after placement, in which values were compared with the control groups and the 1st, 2nd, 3rd or 4th removal torque values in each experimental group. Results: In comparison of the final removal torque tests among experimental groups, the removal torque value of experimental groups except group XII were not statistically different that of control group. And the values of group I and II were significantly higher than the values of group VI, VIII, X, XI, and XII. In addition, the values of group III, IV, and V were significantly higher than group XI and XII. In comparison of the removal torque in the each experimental group, the final removal torque were significantly higher in all groups except group VIII, X, XI, and XII. Conclusion: If sufficient healing time was allowed, a few mobilization of fixture at the very early stage after the implant placement in the rabbits didn't interrupt the final bone to implant osseointegration.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.2
• /
• pp.159-168
• /
• 2004

The effect of xylitol and sorbitol chewing gums on dental caries levels among 5-year old kindergarteners was investigated. Three kindergartens the operations of which were partly subsidized by municipal government of Daegu city, Korea, were chosen as the study sites. The child base of the kindergartens were considered demographically and ethnically similar, representing middle-income families. The subjects were examined at their own kindergarten by the two dentists. Participation in the program was voluntary. Over 12 months, 123 participants chewed xylitol chewing gums(X group; 42 subjects), sorbitol chewing gum(S group; 42 subjects), or did not receive chewing gum as a control group(C group; 39 subjects). Consumption of xylitol and sorbitol was 4.5 to 5.0 g/day/subject, consumed in five daily chewing episodes of 5 min. Oral examination, Dentocult-SM test and interproximal dental plaque collection were completed at baseline and 12 months later. The dmfs of group C increased 59.2%, but group S increased 33.4% and group X increased only 31.3% during 12 months study period. The caries prevention ratio was 47.1% at group X and 43.6% at group S. There also appeared the reduction of caries activity at group X(1.39), group S(1.50) than control group(1.79). Compared with groups S and C, there was a statistically significant reduction of S. mutans in interproximal plaque in group X. The results suggest that xylitol chewing gum can prevent dental caries of deciduous dentition, and may be a little more effective than a sorbitol-containing product in controlling some caries-associated parameters in kindergarten-age subjects.

• Journal of applied mathematics & informatics
• /
• v.10 no.1_2
• /
• pp.167-174
• /
• 2002

A group G is said to be (l, n, n)-generated if it is a quotient group of the triangle group T(p,q,r)=(x,y,z|x$\^$p/=y$\^$q/=z$\^$r/=xyz=1). In [15], the question of finding all triples (l, m, n) such that non-abelian finite simple groups are (l , m, n)-generated was posed. In this paper we partially answer this question for the sporadic group He. We continue the study of (p, q, r) -generations of the sporadic simple groups, where p, q, r are distinct primes. The problem is resolved for the Held group He.

• Environmental Analysis Health and Toxicology
• /
• v.22 no.1 s.56
• /
• pp.73-82
• /
• 2007

Six week-old ICR mite which were divided into four groups including NC, RC, RR and RS were injected with sun ginseng (RS), red ginseng (RR) and saline (RC) intraperitonedlly as an amount of 60 mg/g body weight at 1 hour, 12 hours and 36 hours before the irradiation of high-energy X-ray and the mire were sacrificed at three and a half days after the irradiation. The RS group were significant increase in the weight of spleen (p<0.01) and the numbers of jejunal crypt cells (P<0.01), WBC (p<0.05), lymphocytes (p<0.05) and neutrophils (p<0.05) in comparison with the RC group. The RR group were significant increase in the numbers of jejunal crypt cells (p<0.001), WBC (p<0.05) and neutrophils (p<0.05) in comparison with the RC group. The RS group exhibited a more increase in the weights of spleen and thymus and the numbers of jejunal crypt cells and all items of hematological examination than the RR group. The values of ALT (alanine transaminase) and AST (aspartate transaminase) were significantly elevated (p<0.05) by radiation and they were significantly decreased (p<0.05) in the RS group to the values of the NC group. Taken together the above results, sun ginseng demonstrated a jejunal crypt survival effect, the protective effects on hepatocytes and immune and hematopoietic cells in mice irradiated with high-energy X-ray, and those radiation protective effects were a little higher in comparison with red ginseng.

• Journal of Korean Academy of Nursing
• /
• v.34 no.3
• /
• pp.440-448
• /
• 2004

Purpose: This study was to evaluate the effects of a physical activity reinforcement program on exercise compliance, depression, and anxiety in continuous ambulatory peritoneal dialysis(CAPD) patients. Method: A nonequivalent control group with a pre-post test was designed. Data collection was done from December, 2002 to June, 2003 at a hoapital. The degree of depression and anxiety of the patients was assessed by the score of SCL-90-R, and exercise compliance was measured by exercise period, frequency, time and intensity. The experimental group was composed of 19 participants who were educated based on an exercise education protocol and carried out walking exercises two to four times a week after hearing verbal persuasion biweekly through the telephone or a face-to-face interview for 12 weeks, while 17 participants in control group received no intervention. Result: 1. The experimental group showed significant improvement in self-efficacy of exercise compliance (U=79.00, p=.01), exercise period ($x^2$=20.84, p=.00), exercise frequency ($x^2$=9.03, p=.0l), exercise time ($x^2$=9.03, p=.0l) and exercise intensity ($x^2$=11.09, p=.00) compared to those of the control group. 2. The experimental group showed a lower depression score (U=84.50, p=.01) than the results of the control group. 3. However, there were no changes in anxiety level compared to the control group. Conclusion: The physical activity reinforcement program was found to have an effect on exercise compliance and the depression score of CAPD patients. The results provided evidence for the importance of physical activity and verbal persuasion in CAPD patients.

• Toxicological Research
• /
• v.11 no.2
• /
• pp.205-213
• /
• 1995

This study was undertaken to investigate the effects of organic solvents on xenobiotic metabollzing enzyme system in vivo by meaas of experimental conditions i.e. (1) single group which was treated by benzene (B), toluene (T) and xylene (X), respectively, (2) combination group which was treated by mixture of benzene+toluene (BT), benzene+xylene (BX), and toluene+xylene (TX), respectively, (3) mixture group which was treated by benzene+ toluene+xylene mixture (M), and to interpreat the interaction between the organic solvents metabolizing enzymes. 1. The contents of cytochrome P-450 in liver microsomes were increased (p < 0.01) in organic solvents treated groups, and the contents of cytochrome P-450 were increased by following order of B < T < M < BT=BX < X < TX. 2. The activity of cytochrome P-450 dependent AHHase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the activity of AHHase was increased by following order of B < T < BT=BX=TX=xylene < M. 3. The activity of NADPH P-450 reductase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the order of M < combinated group < X < T

• Applied Chemistry for Engineering
• /
• v.28 no.2
• /
• pp.230-236
• /
• 2017

We synthesized liquid crystalline polymers containing isosorbide group as a cholesteric derivative and methylene group for controlling the transition temperature to the liquid crystal phase. Effects of the concentration of the isosorbide group and the position of the methylene group on the properties of the liquid crystalline polymer were investigated. Among all the synthesized polymers, polymers (MnHI-x) with a methylene group in the main chain showed higher melting transition temperature and thermal stability than those (SnBI-x) with a methylene group in the side chain. All the synthesized polymers showed an enantiotropic liquid crystal phase. The polymers having 10 mol% isosorbide as a cholesteric liquid crystal phase derivative showed nematic phase, and those having 20 mol% or more isosorbide showed a cholesteric or chiral smectic phase. Thus, we can conclude that the isosorbide group plays a role as a cholesteric liquid crystal phase derivative.

• Progress in Superconductivity and Cryogenics
• /
• v.7 no.2
• /
• pp.7-10
• /
• 2005

The magnetic properties of a series of both annealed (biaxially textured) and as-rolled (non-textured) Ni-xW alloy tapes with compositions x = 0,1,3, and 5 at.$\%$, were studied. Characterization methods included XRD analyses to investigate the biaxial cube texturing of the annealed Ni-W alloy tapes and studies of the magnetization M for both annealed and as-rolled Ni-W alloy tapes. Both the isothermal mass magnetizations M(H) of a series of samples at different fixed temperatures and M(T) in fixed field, employing a PPMS-9 (Quantum Design), were measured. The Ni-W alloys have shown much reduced ferromagnetism as W-content x increases. Both the saturation magnetization Msat and Curie temperature Tc decrease linearly with W-content x, and both Msat and Tc go to zero at critical concentration of Xc - 9.50 at. $\%$ W.

• Kyungpook Mathematical Journal
• /
• v.55 no.2
• /
• pp.251-258
• /
• 2015

Let $\mathcal{A}$ be a unital $C^*$-algebra, a, x and y are elements in $\mathcal{A}$. In this paper, we present the expression of the Moore-Penrose inverse and the group inverse of a-$xy^*$ under the conditions $x=aa^+x,y^*=y^*a^+a$, respectively.