• Journal of the Korean Society of Clothing and Textiles
• /
• v.31 no.2 s.161
• /
• pp.197-205
• /
• 2007

We investigated the effects of washing on the mechanical properties and hand values of spandex/cotton and cotton single jersey fabrics. These knitted fabrics were subjected to 30 laundering cycles with a drum-type washer and were followed by drying at $65^{\circ}C$ with a tumble dryer. The mechanical properties of the cotton knitted fabrics changed greatly during the first washing and then suffered no further change in their properties as the number of washing cycle increased. However, the properties of the spandex/cotton knitted fabrics changed continuously throughout all the washing cycles. The cotton/spandex knitted fabrics showed higher values in tensile and bending properties than did the cotton knitted fabrics, though both kinds of fabrics showed less difference in shearing, surface and compression properties. The spandex/cotton knitted fabrics which had proper density had a higher THV for winter underwear after 30 repeated washings than did the cotton knitted fabrics, and the THVs of both fabrics decreased with the increase in the number of washing cycles.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.18 no.1
• /
• pp.102-110
• /
• 2012

Purpose: The purpose of this study was to evaluate the effects of BLS training in nursing students and their retention period. Methods: The participants were 48 nursing students enrolled in M University in Mokpo. Data were collected from September, 2009 through September 2010. Nursing students were tested for their knowledge, attitude, confidence before, immediately after, 4 weeks after, 8 weeks after, 6 months after, and 1 year after BLS training. In addition, their knowledge and skill of cardiopulmonary resuscitation were tested 5 times. Data were analyzed using the SPSS/PC 12.0 statistical program Results: Knowledge, attitude and confidence were significantly increased immediately after compared to before BLS training. Knowledge and confidence 6 months after, and attitude, performance ability and technical precision for ventilation and compression 4 weeks after BLS training were significantly decreased compared to immediately after. Conclusion: Overall retention of BLS training effects among nursing students, without reinforcement, decreases significantly after six months following initial training. BLS training in nursing students should be repeated every six months, especially performance training of BLS should be repeated every 4 weeks. In addition, to maintain the knowledge and skills of BLS, appropriate renewal time of certification and improvement of training programs are necessary.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.30 no.5
• /
• pp.407-416
• /
• 2008

Purpose: The aim of the present study is to evaluate the effect of repetitive distraction and compression on new bone formation during distraction period. Materials and methods: Sixteen healthy rabbits, weighing about 2.5kg, were used in this experiment. A unilateral mandibular osteotomy was performed in the left mandible and the distractor(Track 1 $plus^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany) was fixed with four screws (Cross driver screw $TI^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany). After 4 days, the mandibles were distracted at a rate of 0.6mm/day for 10 days to obtain the amount of 6mm distraction in the control group(n=4). In the experimental group A(n=6), they were distracted at a rate of 1.2mm/day for 5 days and then compression of 0.6mm length and distraction of 0.6mm per 12 hours were carried out as counter direction for 5 days, relatively. In the experimental group B(n=6), distraction of 1.2mm length and compression of 0.6mm length per 12 hours were repeated for 10 days to obtain the amount of 6mm distraction finally. The experimental animals were sacrificed at 2 and 4 weeks after surgery and block specimens were obtained. With histologic and histomorphometric analysis, we observed the histologic changes of the cells and bone formation after H-E and Masson- Trichrome staining and then, measured Bone Deposition Rate with TOMORO $ScopeEye^{TM}$ ver. 3.5(Olympus, Japan), Results: Histologically, new bone formation was examined in all experimental groups and the control. But, the ability of bone formation of the experimental group A was somewhat better than any other groups. On the histomorphometric analysis, Bone Deposition Rate was higher in the experimental group A$(50.67{\pm}4.36%)$ than in the control group$(45.94{\pm}3.97%)$ and in the experimental group B$(42.68{\pm}5.70%)$. These data showed significant differences statistically(p<0.05). Conclusion: These results show that the distraction osteogenesis using repetitive compression and distraction force in the early consolidation period may be effective for new bone formation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.12
• /
• pp.2641-2646
• /
• 2011

In this paper, we studied that the EZW algorithm based in HWT was proposed effective compression technique of wavelet transformed image. The proposed Haar-EZW algorithm is that image was coding by zerotree coding technique using self-similarity of HWT coefficients. If the HWT coefficient is larger than the threshold, that is coding to POS. If the HWT coefficient is smaller than the threshold, that is coding to NEG. If the HWT coefficient is larger than the root of zerotree, that is coding to ZTR. If the HWT coefficient is smaller then the threshold, and if that is not the root of zerotree, that is coding to IZ. This process is repeated until all the HWT coefficients have been encoded completely. This paper is compared Haar-EZW algorithm with Daubechies and Antonini. As the results of compare, it is shown that the PSNR of the Haar-EZW algorithm is better than Daubechies's and Antonini's.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.2 no.4
• /
• pp.19-28
• /
• 2009

This paper is a study on method that the EZW algorithm is proposed effective compression technique of wavelet transformed image. The EZW algorithm is encoded by zerotree coding technique using self-similarity of wavelet coefficients. If the coefficient is larger than the threshold a POS coded, if the coefficients is smaller than minus the threshold a NEG is coded. If the coefficient is the root of a zerotree than a ZTR is coded and finally, if the coefficient is smaller then the threshold but it is not the root of a zerotree, than an IZ is coded. This process is repeated until all the wavelet coefficients have been encoded completely. This paper was compared to EZW algorithm and a widely available version of JPEG. As the results of compare, it is shown that the PSNR of the EZW algorithm is better than JPEG.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.5
• /
• pp.103-109
• /
• 2019

The pressure reducing valve for water is controlled by the load of the compression spring and the force of the fluid acting on the diaphragm of the stem. Repeated upward and downward reciprocation of the pressure-reducing valve stem damages the diaphragm, resulting in leakage. In this study, we designed a stem without a diaphragm and adjusted the stiffness of the compressing spring. In order to select the spring stiffness, springs offering a stiffness of -20%, -10%, 0%, and 10% with respect to the stiffness of the compression spring attached to the existing pressure reducing valve stiffness. A prototype for the pressure reducing valve was fabricated and the pressure change was evaluated for the target static pressure (6 bar) by testing the pressure characteristics after mounting the modified stem and each compression spring. Evaluation of the pressure characteristics was carried out using ASSE 1003 and KS B 6153. In addition, the flow rates were compared by internal flow analysis of the conventional pressure reducing valve and the pressure reducing valve using the modified stems, and the flow analysis was performed using Solidworks flow simulation 2018. The spring stiffness was constantly discharged at the target static pressure of 3.793 kgf/mm, and the flow rate was increased by about 15% compared with the conventional pressure reducing valve.

• Steel and Composite Structures
• /
• v.38 no.2
• /
• pp.151-164
• /
• 2021

During the pipe forming process, a steel plate undergoes inelastic behavior multiple times under a load condition repeating tension and compression in the circumferential direction. It derives local reduction or increase of yield strength within the thickness of steel pipes by the plastic hardening and Bauschinger effect. In this study, a combined hardening model is proposed to effectively predict variations of yield strength in the circumferential direction of API-X65 and X70 steel pipes with relatively low t/D ratio during the forming process, which is expected to experience accumulated plastic strain of 2~3%, the typical Lüder band range in a low-carbon steel. Cyclic tensile tests of API-X65 and X70 steels were performed, and the parameters of the proposed model for the steels were calibrated using the test results. Bending-flattening tests to simulate repeated tension and compression during pipe forming were followed for API-X65 and X70 steels, and the results were compared with those by the proposed model and Zou et al. (2016), in order to verify the process of material model calibration based on tension-compression cyclic test, and the accuracy of the proposed model. Finally, parametric analysis for the yield strength of the steel plate in the circumferential direction of UOE pipe was conducted to investigate the effects of t/D and expansion ratios after O-forming on the yield strength. The results confirmed that the model by Zou et al. (2016) underestimated the yield strength of steel pipe with relatively low t/D ratio, and the parametric analysis showed that the t/D and expansion ratio have a significant impact on the strength of steel pipe.

• Journal of the Korean Geotechnical Society
• /
• v.25 no.8
• /
• pp.95-106
• /
• 2009

This study was intended to identify the effect of the wetting on a long-term compression settlement of the rock/soil mixture used as fill material, depending on compaction and grading conditions. The relatively large settlement happened under the fully-submerged condition, and a repeated settlement was monitored when moisture content increased over and over again like the rainfall infiltration. In case of the materials without fine fractions or compacted in wet condition, the settlement caused by wetting was relatively low. In conclusion, the long-term compression settlement of granular (rock/soil mixture) fill material is more affected by the increase of water content and temperature change (freezing and thawing) than creep.

• Korean Journal of Food Science and Technology
• /
• v.31 no.1
• /
• pp.138-146
• /
• 1999

Textural properties of the cooked wheat noodles prepared from 5 Korean wheat varieties (Woori, Yeunpa, Allgeuru, Geuru, and Tapdong), and 3 foreign wheat varieties (ASW, WW and DNS) were evaluated by mechanical and sensory analyses, and their correlations to the physicochemical properties of the flours were examined. Cooking loss for noodle was negatively correlated with protein content, and weight increase during cooking showed a positive correlation with damaged starch content. From the mechanical tests, hard wheats (Tapdong and DNS) showed greater values for hardness, chewiness and tensile strength of the noodles than soft wheats. Foreign soft wheats (ASW and WW) showed relatively lower values for these attributes than the Korean soft wheats. Among the mechanical tests, multi-blade compression shear test had better correlations to the sensory characteristics than 10% compression, repeated compression and tensile tests. Among the flour characteristics, protein content was the most determining factor for the textural properties of noodle. Amylose increased the tenderness and slipperiness, but decreased internal firmness of the noodle. The Korean soft wheat noodles showed relatively darker color for the cooked noodle than WW or ASW. From acceptability test for noodle, Geuru was most preferred among the tested wheat varieties.

• Journal of Korean Neurosurgical Society
• /
• v.53 no.2
• /
• pp.125-128
• /
• 2013

A 65-year-old man who had lateral cervical disc herniation underwent cervical posterior laminoforaminotomy at C5-6 and C6-7 level right side. During the operation, there was no serious surgical bleeding event. After operation, he complained persistent right shoulder pain and neck pain. Repeated magnetic resonance image (MRI) showed diffuse cervical epidural hematoma (EDH) extending from C5 to T1 level right side and spinal cord compression at C5-6-7 level. He underwent exploration. There was active bleeding at muscular layer. Muscular active bleeding was controlled and intramuscular hematoma was removed. The patient's symptom was reduced after second operation. Symptomatic postoperative spinal EDH requiring reoperation is rare. Meticulous bleeding control is important before wound closure. In addition, if patient presents persistent or aggravated pain after operation, rapid evaluation using MRI and second look operation is needed as soon as possible.