• Tribology and Lubricants
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• 제33권2호
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• pp.45-51
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• 2017

Engine oil is a substance used for the lubrication of internal combustion systems. However, in some case, defects in engine systems may contaminate engine oil with fuel. Contaminated engine oil can cause problems in the normal functioning of a vehicle. In this study, we investigate the functional properties of engine oil contaminated with diesel fuel. The test results indicate that the engine oil contaminated with diesel fuel has low flash point, pour point, density, kinematic viscosity and cold cranking simulator value. The contaminated engine oil which has low plash point can cause fire and explosion accident. Furthermore, a four ball test indicates that the contaminated engine oil increases wear scar to poor lubricity. Moreover, we investigate the GC pattern using SIMDIST (simulated distillation) for determination of diesel in engine oil. The SIMDIST analytic result, diesel was detected at earlier retention time than engine oil in chromatogram. Thus the SIMDIST method can define whether engine oil is contaminated by diesel fuel or not. We can use the SIMDIST method for the diagnosis of oil condition instead of analyzing other physical properties that require many analytic instruments, large volume of oil sample and long analysis time.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.663-668
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• 2000

In this study, the Atterberg limit and grain-size analysis were carried for the purpose of investigating the influence on drying and organic matter of Ulsan marine deposited clay. The results revealed that Atterberg limit was decreased and grain-size distribution was variable on drying. The presence of organic matter also influenced on the physical properties of the soils. The physical properties of marine deposited clay were variable on drying, so that we recommended grain-size analysis and Atterberg limit test were performed under the wet condition of the soils after sampling.

• The Journal of the Acoustical Society of Korea
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• 제15권4E호
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• pp.3-8
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• 1996

The bubble size distribution is critical information to understand sound propagation and ambient noise in the ocean. To estimate the bubble size distribution in a bubbly water, the sound attenuation has been only in the conventional acoustic bubble sizing method without considering the sound speed variation. However, the effect of the sound speed variation in bubbly water cannot be neglected because of its compressibility variation. The sound attenuation is also affected by the sound speed variation. In this paper, a coherent acoustic bubble sizing inverse technique is introduced as a new bubble sizing technique with considering sound speed variation as well as the sound attenuation. This coherent sizing method is theoretically verified with the bubble distribution functions of single-size, Gaussian, and power-law functions. Its numerical test results with the coherent acoustic bubble sizing method show good agreement with the given bubble distributions.

• 한국패션뷰티학회지
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• 제6권1호
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• pp.16-20
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• 2008

Ubiquitous computing which is called, the innovation of the 21st Century is a core technology of next generation. RFID technology is noticed, and physical distribution, home network, telematics, like industry automatization are developed by using various technique. Particulary, They use RFID technology for fashion and beauty industry, So, supplying network management, physical distribution management and warehouse management are investigated for the automatization. What we have investigated so far, a traceability system is made of ubiquitous sensor network for monitoring fashion and beauty industry environment. The proposed system using EPC network can provide information of industrial products traceability quickly and efficiently. Moreover, this system with RFID Technology gives intelligence of distribution and record. In this paper, We recommend the vision of Ubiquitous convergence of fashion and beauty industry.

• Communications for Statistical Applications and Methods
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• 제23권2호
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• pp.147-161
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• 2016

This paper introduces the four parameter new generalized inverse Weibull distribution and investigates the potential usefulness of this model with application to reliability data from engineering studies. The new extended model has upside-down hazard rate function and provides an alternative to existing lifetime distributions. Various structural properties of the new distribution are derived that include explicit expressions for the moments, moment generating function, quantile function and the moments of order statistics. The estimation of model parameters are performed by the method of maximum likelihood and evaluate the performance of maximum likelihood estimation using simulation.

• 국제물리치료학회지
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• 제9권3호
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• pp.1537-1542
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• 2018

This study aimed to identify the effects of kinesio taping (KT) applied in a proprioceptive neuromuscular facilitation (PNF) pattern on the pain, weight-bearing distribution (WBD), and walking ability of knee osteoarthritis (KOA) patients. Thirty women with KOA were randomly allocated to a control group (n=15) with KT at the quadriceps only, and a PNF pattern group (n=15) with KT at the quadriceps and gastrocnemius muscle. Pain intensity was measured using a visual analogue scale during walking. In addition, WBD, and walking ability were measured before and 30 minutes after KT application. The VAS significantly reduced in both groups after the intervention (p<.05). WBD (p<.05, ES=.32) and walking ability (p<.05, ES=.38) showed a significant change in the PNF pattern group, and in the inter-group comparison, the PNF pattern group showed a significant difference compared to the control groups. These results demonstrate that KT application with PNF pattern effectively attenuate the pain and improves WBD and walking ability in KOA patients.

• 국제물리치료학회지
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• 제9권3호
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• pp.1543-1548
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• 2018

The purpose of this study was to analyze the effects of manual therapy on lower extremity alignment in pelvic malalignment. The subjects were 20 adults with pelvic malalignment. They were divided into two groups: manual therapy group (n=10) and stretching exercise group (n=10). Each group performed the intervention two times per week for 4 weeks. The lower extremity alignment was measured by pelvic deviation, functional leg length inequality, and plantar pressure distribution, which were measured between pre- and post-test. In the result of pelvic deviation, there was a significant difference between the pre- and post-test of the manual therapy group and stretching exercise group. In the result of the functional leg length inequality, there was a significant difference between the pre- and post-test of the manual therapy group. In the result of plantar pressure distribution, there was a significant difference between the pre- and post-test of the manual therapy group. These findings suggest manual therapy improves the pelvic deviation, functional leg length inequality, and plantar pressure distribution in the pelvic malalignment.

• 한국전문물리치료학회지
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• 제12권1호
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• pp.80-90
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• 2005

The purpose of this study was to evaluate the effects of pulsed ultrasound on wound healing and observe during the wound healing process the distribution of mast cells according to histopathologic findings. Eighty Sprague Dawley rats which were divided into 4 groups received full thickness skin wounds on the back. Each of the 5 animals was sacrificed immediately and then sacrificed again 1, 3, 6, and 12 days after injury. Specimens from the wounds were removed during healing and routinely processed with a hematoxylin-eosin stain and a toluidine blue stain. The authors then observed the distribution of mast cells under a light microscope. The results of this study were as follows: The rate of wound healing and the length of the wounds of the pulsed ultrasound group II was significantly faster than group I on day 6 and day 12 (p<.001). Group III showed the most significant effect after12 days (p<.001). Group IV also showed a significant effect at 12 days (p<.01). A low-intensity ultrasound .5 $W/cm^2$ resulted in a fast healing rate. During the wound healing process mast cells had a tendency to decrease in the acute inflammatory phase. During the wound healing process mast cells were thought to contribute to the healing of the wound.

• PNF and Movement
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• 제5권2호
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• pp.37-46
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• 2007

Purpose : The purpose of this study was to examine the effects of combination of isotonic and rhythmic stabilization in proprioceptive neuromuscular facilitation on trunk stability and balance in elderly people with chronic low back pain. Subjects : Thirty-two elderly people ($73.78{\pm}8.49$ years of age) who had complaints of CLBP were randomly assigned to 2 groups: experimental group and control group. Methods : Subject trained with combination of isotonic and rhythmic stabilization in proprioceptive neuromuscular facilitation for 4weeks with aim of improving trunk stability and balance. Weight distribution, trunk muscle balance, static balance ability and dynamic balance ability were measured before, at the end of training. Results : Data were analyzed using two-way ANOVA. After the exercise programs, there were significant differences in the weight distribution, trunk muscle balance and dynamic balance ability between the experimental and control group. However there was no significant difference in the one leg stance test(p<.05). Conclusion : This study suggest that PNF programs may be appropriate for improving trunk stability and balance in elderly people with CLBP.

• Nuclear Engineering and Technology
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• 제41권5호
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• pp.677-690
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• 2009

A previous study demonstrated that the two-row fuel assembly has much more favorable neutron-physical and thermal-hydraulic behavior than the conventional one-row fuel assemblies. Based on the newly developed two-row fuel assembly, an SCWR core is proposed and analyzed. The performance of the proposed core is investigated with 3-D coupled neutron-physical and thermal-hydraulic calculations. During the coupling procedure, the thermal-hydraulic behavior is analyzed using a sub-channel analysis code and the neutron-physical performance is computed with a 3-D diffusion code. This paper presents the main results achieved thus far related to the distribution of some neutronic and thermal-hydraulic parameters. It shows that with adjustment of the coolant and moderator mass flow in different assemblies, promising neutron-physical and thermal-hydraulic behavior of the SCWR core is achieved. A sensitivity study of the heat transfer correlation is also performed. Since the pin power in fuel assemblies can be non-uniform, a sub-channel analysis is necessary in order to investigate the detailed distribution of thermal-hydraulic parameters in the hottest fuel assembly. The sub-channel analysis is performed based on the bundle averaged parameters obtained with the core analysis. With the sub-channel analysis approach, more precise evaluation of the hot channel factor and maximum cladding surface temperature can be achieved. The difference in the results obtained with both the sub-channel analysis and the fuel assembly homogenized method confirms the importance of the sub-channel analysis.