• Journal of Oriental Neuropsychiatry
• /
• v.16 no.2
• /
• pp.25-34
• /
• 2005

Background and Objectives There was no clinical data except literary study on mutual correlation with autistic disorder in Western medical diagnosis and five kinds of flaccidity in infants(五軟), five kinds of retardation(五遲) in Oriental medical diagnosis. This study was performed to investigate the correlation of five kinds of flaccidity in infants(五軟), five kinds of retardation(五遲) to the children with autistic disorder and to set the time table for clinical diagnosis of developmental retardation by making a comparative study of normal developmental children so we can treat the children with autistic disorder in good time. Method We made the comparative study of interview sheets recorded by parents of total 163 children who were diagnosed as autistic disorder who visited HaeMa Oriental Medical Clinic with interview sheets recorded by parents of generally accepted normal developmental children(263) and then we took statistics. Results : 1. There was significant correlation with speech and walking among five kinds of flaccidity in infants(五軟), five kinds of retardation(五遲) in autistic disorder statistically and clinically in comparison with normal children. 2. There wasn't significant correlation with growth time of tooth among five kinds of flaccidity in infants(五軟), five kinds of retardation(五遲) on diagnosis of autistic disorder in comparison with normal children. 3. There was significant correlation with retardation of times going to toilet by oneself (it does not consist in five kinds of flaccidity in infants(五軟), five kinds of retardation(五遲).) in both of autistic disorder. Conclusion Autistic disorder was significantly correlated with the faculty of speech(語遲), retardation in walking out(行遲) of five kinds of flaccidity in infants(五軟), five kinds of retardation(五遲). We need to concrete the index of diagnosis, because it is so difficult to measure times and register retardation in tooth eruption(齒遲), retardation in hair-growing(髮遲), debility of neck and nape(頭項軟), flaccidity of extremities(手軟) and flaccidity of muscle(肌肉軟). And we can also use times going to toilet by oneself as one of diagnostic criteria because of its significant correlation. It is required to make early diagnosis of five kinds of flaccidity in infants(五軟), five kinds of retardation(五遲) using these criteria, and to treat them early by oriental medicine.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.8 s.179
• /
• pp.2074-2082
• /
• 2000

In this study, to investigate and to predict the crack growth behavior under variable amplitude loading, crack growth tests are conducted on 7075-T6 aluminum alloy. The loading wave forms are generated by normal random number generator. All wave forms have same average and RMS(root mean square) value, but different standard deviation, which is to vary the maximum load in each wave. The modified Forman's equation is used as crack growth equation. Using the retardation coefficient D defined in previous study, the load interaction effect is considered. The variability in crack growth process is described by the random variable Z which was obtained from crack growth tests under constant amplitude loading in previous work. From these, a statistical model is developed. The curves predicted by the proposed model well describe the crack growth behavior under variable amplitude loading and agree with experimental data. In addition, this model well predicts the variability in crack growth process under variable amplitude loading.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.17 no.2
• /
• pp.63-68
• /
• 2017

Gaucher disease (GD) is caused by the deficiency of glucocerebrosidase. In pediatric patients with GD, especially Type I GD, enzyme replacement therapy (ERT) can reduce the hepatosplenomegaly and improve the hematologic finding and growth velocity. Herein, we report a 2-year-old girl with Type I GD presented with hepatosplenomegaly, bone pain and growth retardation. A 2 year-old-girl was referred to our hospital due to severe hepatosplenomegaly and growth retardation. She suffered from both leg pain and chronic fatigue. Simple x-ray showed widened distal long bones like that of an 'Erlenmeyer flask' which is associated with GD. The laboratory test showed anemia and thrombocytopenia. The enzyme activity was markedly reduced and the direct sequencing of the GBA gene showed the compound heterozygous mutations, p.G46E and p.L444P. As the G46E have been considered as the protective gene against neuronopathic genotype, we could assess the Type I GD in this patient. After one year of ERT, the growth velocity became 11 cm per year. Bone pain and fatigue disappeared. The volume of liver and spleen was reduced from $683cm^3$ and $703cm^3$ to $590cm^3$ and $235cm^3$, respectively. Although GD is an extremely rare disease in Korea, growth retardation and bone pain in children are the important signs which lead to early detection of GD and a simple radiologic finding is helpful to assess the GD at outpatient clinic. We highlight that the early diagnosis and early ERT is important for good growth and outcome for pediatric patients with GD.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.6 no.4
• /
• pp.80-88
• /
• 1997

An experimental investigation of the fatigue through crack growth behavior under simple stepped variable loading condition has been performed using Al7075-T651. Experiments were carried out by using cantilever bending type specimens, with chevron notches on a small electro-magnetic test machine. Tensile overloads have a retarding effect on the fatigue crack growth rates, therefore tensile overloads were used for the beneficial effect on the fatigue life. While in most cases compressive overloads have only a vanishing effect on crack growth rates, some experiments with single edge crack tension specimens reveal a marked growth retardation. The stress ratios used in this investigations varies from R=0.32 to 0.81, from R=0.04 to 0.76, from R=-0.15 to 0.73, and from R=-0.33 to 0.68 and the peak load for each case was not varied. The crack growth and crack closure were measured by Kikukawa's compliance method with a strain gauge mounted on the backside of each specimens. The results obtained are as follows. When the stepped variable load was applied, the smaller the stress ration was, the larger the delayed retardation of the crack growth rate was. The fatigue crack growh rate data obtained for through cracks were plotted well against the effective stress intensity factor range from 4.0 to 20.0MP{a^{SQRT}m}. It was found that the effective stress intensity factor range ratio was related well to the opening stress intensity factor, the maximum stress intensity factor, and crack length.

• Journal of Welding and Joining
• /
• v.6 no.2
• /
• pp.56-63
• /
• 1988

The effects of PWHT (poste weld heat treatment) and stress simulating the residual stress during PWHT in weld HAZ of low and high strength steels on corrosion fatigue crack growth were evaluated. The obtained results are summarized as follows. 1. Fatigue crack growth rate of HAZ in air and 3.5% NaCl solution was slower than that of parent due to the signgularity in weld HAZ. 2. In the case of HT-80, 3.5% NaCl solutio nacts to accelerate the crack growth for all specimens, and the sensitivity of as-weld to corrosion environment was the greatest among other PWHT specimens. 3. Corrosion fatigue crack growth of parent, as-weld and PWHT speciments ofr SS41 as well as SM53B was retarded in comparison with the fatigue crack growth in air. 4. There was a tendency that crack growth of PWHT specimens subjected $10kg/mm^2$ was faster than that of PWHT specimens without stress during PWHT. 5. The retardation phenomenon of crack growth in corrosion environment is attributed to the crack branching decreased .DELTA.K due to the corrosion products and multi-cracks.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2002.10a
• /
• pp.73-78
• /
• 2002

Ships and ocean structures are generally under random loading. Various type of variable-amplitude loading affects fatigue crack growth and fatigue life. However interaction effects due to irregularity of loading including random loading have not explained exactly and it is difficult to examined fatigue crack growth behaviour and fatigue life for this reason. Therefore in this paper crack growth tests with constant-amplitude loading including a single overload were conducted to measure plastic zone size near crack tip of DENT specimen. And the observed plastic zone sized were discussed in terms of crack growth rate. As a result of this the effect the plastic rue size due to the overload is examined on the effect on crack growth rate and, consequently, fatigue life.

• Journal of Aerospace System Engineering
• /
• v.1 no.1
• /
• pp.45-52
• /
• 2007

This paper analyzed the extension effects of fatigue life and the application of pre-indentation in aircraft structural material such as aluminum alloys. The test specimen used the thin sheet of aluminum alloy with a single-edged notch. The experiments were conducted after making the pre-crack under a constant amplitude loading. As the fatigue life extension technique, the pre-indentation making an indent on the predicted path of crack propagation was applied. The work presented here discussed about a proper mathematical relation between crack growth rate and the range of stress intensity factor and about the generalization of crack growth mechanism with large retardation effect. A technique to enhance the applicability of pre-indentation if also mentioned.

• Composites Research
• /
• v.12 no.3
• /
• pp.1-7
• /
• 1999

New hybrid composite material CPAL(Carbon Patched ALuminum alloy), an Al2024-T3 plate doubleside reinforced with carbon/epoxy laminates were made. Fatigue crack growth tests were carried out at R=0.2, 0.5 in the CPAL specimens. The retardation mechanism and behavior of fatigue crack growth were examined basing on investigation of the crack and the delamination using a X-Ray and a ultrasonic C-Scan. The fatigue crack growth rates of CPAL specimens were remarkedly retarded compared to that of the Al2024-T3 specimen. The retardations amounts of the fatigue crack growth rates get higher in $0^{\circ}$/$90^{\circ}$ CPAL specimen than in $\pm$$45^{\circ}$ CPAL specimen, and get higher at R=0.2 than at R=0.5. The retardation of fatigue crack growth rates in CPAL specimen was generated by the crack bridging mechanism, that is the behavior that the fibers in CFRP layers decrease the COD in the Al2024-T3 plate.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.481-485
• /
• 1997

6063-T5 alloys are tested in laboratory air, water and 3% NaCl solution to investigate the effects of corrosive environment on the retardation behavior through single overload fatigue test. Also, the fatigue crack propagation and the crack closure behavior are studied. The results obtained in this experimental study are summarized as follows: 1) Behaviors of fatigue crack growth retardation are observed in water and 3% NaCl solution as they do in air. The number of delay cycles and the size of affected region by single overload decrease greatly in water and 3% NaCl compared with those in air. 2) In fractographic results, the overload marking by single overload appear remarkably in air, but indistinctly in water and 3% NaCl solution. 3) The effect of crack closure on crack propagation is most remarkable in the beginning of crack propagation. With crack propagation, the crack closure level and its effect decrease greatly.

• Asian Journal of Turfgrass Science
• /
• v.3 no.1
• /
• pp.24-33
• /
• 1989

This study was conducted to investigate the effect of paclobutrazol [(2 RS , 3 RS )1-(4- chlor-ophenyl )-4, 4- dimethyl -2- (1, 2, 4- triazol -1- yl )- pentan -3-01] on the tolerance of hi-gh temperature and drought stress as related to growth retardation , iranspiration rate , soil water content , nitrogen level and photosynthetic rate in perennial ryegrass ( Loliurn perenne L . ' Omega H , ). Plants were given a 30 ml soil drench of paclohutrazol at the concentrations of 0, 0.01, 0.1, 1.0, 10.. 0, mg / 6 .5cm- diameter pot . The rcsults were as follows : 1. Increasing concentrations of paclohutrazul reduced plant height , leaf area , fresh weight and dry weight , hut increased chlorophyll content per unit area . The number of tillers and leaf width were not affected hy the paclobutrazol concentrations . 2. The proper concentration of paclohatrazol on growth retardation in perennial ryegrass was about I mq /pot , hut leaf deformity and severe growth retardation were shown at high concentration of 10 mq / pot . 3. Perennial ryegrasses grown at 30˚C were shown significantly short plant height and low leaf nitrogen level compared with those grown at 20˚C. Increasing concentrations of paclohutrazol at 20˚C increased nitrogen level hut it could not increase nitrogen level at 30˚C . 4. During the drought stress , increasing temperatures significantly promoted transpiration rate and wilting time . It took about 5 days at 20˚C and 3 days at 30˚C to reach wilting time of leaves from water stress treatment . Soil water contents at wilting time of non-treated controls were averaged 6. 871% at 20˚C and 6. 17% at 30˚C 5. Paclohutrazol reduced transpiration rate at high temperature and drought stress . Wilting appeared at the lower water content of soil according to increasing concentrations of paclobutrazol at 30˚C hut there were no differences among concentrations of at 20˚C. 6.Paclohutrazol treatment at 1 rag /pot reduced injury rate of leaves from 67.1 % and 100 % in control plants to 15.7% and 80% at 20˚C and 3010, respectively. 7. Photosynthetic rate per unit area was significantly reduced at high temperature . Paclohutrazol stimulated photosynthetic rate with increase of concentrations at 20˚C but there was no increasing effect at 30˚C.