• Title/Summary/Keyword: Recovery method

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Analysis of Durability of Torsion Beam Axle Using Modal Stress Recovery Method (모달 응력 회복법(Modal Stress Recovery)을 이용한 Torsion Beam Axle 내구해석)

  • Ko, Jun-Bok;Lim, Young-Hoon;Lee, Dong-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.10
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    • pp.1339-1344
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    • 2010
  • MSM (Modal Superposition Method) is a technique for analyzing structural durability by taking the vibration characteristics into consideration. In this paper, MSR (Modal Stress Recovery) method, which is similar to MSM, was reviewed to check its validity as a durability analysis method. The MSR method directly calculates the modal displacement time history in multibody dynamics analysis; as a result, the total analysis time is shorter than that of MSM method. We conduct durability analysis using the MSR method and a durability test of a torsion beam axle that is affected by various road loads within the natural frequency of the beam axle. The analysis results for critical location and durability were in good agreement with the respective test results. Therefore, durability analysis using the MSR method is effective in predicting the durability of the structures of various dynamic systems.

Comparison of Analytical Methods for α-Quartz by FTIR and XRD (FTIR과 XRD를 이용한 α-Quartz 분석법 비교)

  • Kim, Boo-Wook;Lee, Jong-Seong;Choi, Byung-Soon
    • Journal of Environmental Health Sciences
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    • v.35 no.2
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    • pp.130-142
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    • 2009
  • This study compared FTIR with XRD method for the analysis of quartz by % recovery, coefficient of variation (CV) and influence of the interference. the results were as the following. 1. In FTIR method, the coefficient of determination ($r^2$) was 0.9998 in a calibration curve of $695\;cm^{-1}$, and the limit of detection was $4.9{\mu}g/sample$. 2. The highest recovery was $799\;cm^{-1}$ (98.2%). 3. The CVpooled of the FTIR method was approximately 10% in three wave numbers. 4. The analysis of qualitative and quantitative for quartz is difficult with mixed cristobalite and iron oxide. 5. In XRD method with rotating sample holder and LynxEye detector, the coefficient of determination was 0.9996 in a calibration curve, and the limit of detection was $5.9{\mu}g/sample$. 6. The recovery and CV pooled were 104.3%, and 11 %, respectively. 7. In muffle furnace ashing, the quartz weight decreased to 34% when the maximum weight of the iron oxide was more than eight times. In conclusion, the accuracy (% recovery) and precision (CV) of FTIR and XRD method for analyzing $\alpha$-quartz were similar. FTIR method was a disadvantage for sample matrix because it indicates possibility of interference. However, XRD method distinguished specific crystalline forms of silica, and the majority of silicate minerals. In addition, XRD method recommend filter dissolution to pretreatment method.

A study on simultaneous determination of residual sulfonamides in livestock productions by high performance liquid chromatography (HPLC를 이용한 축산식품중 잔류 설폰아미드제의 동시분석법 연구)

  • 황래홍;김영수;윤은선;김기근;이규학
    • Korean Journal of Veterinary Service
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    • v.18 no.3
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    • pp.13-28
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    • 1995
  • This study was carried out to explore the most sensitive and useful method for simultaneous determination of five sulfa drugs(sulfamethazine, sulfamerazine, sulfamonomethoxine, sulfadimethoxine, sulfaquinoxaline) in livestock productions(pork muscle, bovine muscle, chicken muscle, milk ) by HPLC with UV detector and reverse phase column. The results obtained were as follows:1. For mobile phase acetonitrile-0.01M ammonium acetate (23:77) showed more applicable sensitivity and retention times than acetonitrile-1% acetic acid(23:77). Thus acetonitrile-0.01M ammonium acetate(23:77) selected and applied to the modification test, from which it was found pH 6.75 was the most adequate. 2. Optimal wavelength of UV for SMT(sulfamethazine), SMR(sulfamerazine), SMM(sulfamonomethoxine), SD(sulfadimethoxine), and SQ(sulfaquinoxaline) were 266, 266, 265, 269 and 250nm, respectively, and that for simultaneous application it was 263nm. 3. The average recovery rate by extractant(chloroform, dichloromethane, chlorform+dich-loromethane) in the classic method was not significantly different(p>0.05) but that by chloroform higher than the others. Thus chloroform was found to be adequate as extractant in this classic method. 4. The average recovery rate was 86.5% by the MSPD(matrix solid phase disperse) method, which was significantly higher than that by the classic method(p<0.05). Also the recovery rates by method were significantly different(p<0.05) in accordance with sample and type of drug. The MSPD method was much superior to classic method on clean-up.

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Analysis of Residual Solvents in Food Packaging Materials Using Solid Phase Microextraction Method (Solid Phase Microextraction법을 이용한 식품포장재 중의 잔류용제 분석)

  • 서택교;박상현;이윤수;김정한;권익부
    • Journal of Food Hygiene and Safety
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    • v.14 no.1
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    • pp.76-83
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    • 1999
  • Solid phase microextraction (SPME) was used for the determination of 6 standard solvents (methanol, isopropanol, methyl ethyl ketone, ethyl acetate, cyclohexane, toluene) in food packaging materials. SPME method is a solvent-free sample preparation technique in which a fused silica fiber coated with polymeric organic liquid is introduced into the headspace above the sample. SPME method using fiber coated polydimethylisiloxane (PDMS) was compared with static headspace (SHS) method used as a reference. It was found that the optimal adsorption condition using PDMS-SPME method was 2$0^{\circ}C$ for 15 minutes for the standard solvents. Detection limits, linearity, reproducibility and recovery of both SHS and PDMS-SPME methods have been determined using 6 standard solvents. Both methods were characterized by high reproducibility and good linearity. Using SHS methods, the mean recovery of the 6 standard solvents was ranged from 75.5% to 105.8% with a mean relative standard deviation (RSD) of 0.3% to 4.8%. With PDMS-SPME method, the mean recovery of the 6 standard solvents was ranged from 86.7% to 108.3% with a mean RSD of 0.4% to 2.5%. The detection limits of both methods were the same for toluene, cyclohexane and methyl ethyl ketone; those of PDMS-SPME method were higher than those of SHS method for methanol, isopropanol and ethyl acetate. PDMS-SPME fiber shoed excellent adsorption for non-polar solvents such as toluene, while it showed relatively low adsorption for polar solvents such as methanol.

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The Effects of Semi-Fowler's Position on Post-Operative Recovery in Recovery Room for Patients with Laparoscopic Abdominal Surgery (복강경 수술 후의 반좌위가 수술직후 회복정도에 미치는 영향)

  • Kim, Kyung Ah;Kim, Yeong Kyeong
    • Korean Journal of Adult Nursing
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    • v.16 no.4
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    • pp.566-574
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    • 2004
  • Purpose: To find the effects of semi-Fowler's position on the post-operative recovery for patients with laparoscopic abdominal surgery in recovery room. Method: The research was performed by nonequivalent control group non-synchronized quasi-experimental design. The subjects are forty patients who had laparoscopic abdominal surgery in a hospital from Aug. thru Nov. of 2003. Post-recovery scores and $O_2$saturation degree were measured. The experimental group was place in semi fowler's position while the control group was placed in supine position. The homogeneity between the control group and experimental group was analyzed using the Chi-square, and the hypothesis were tested using t-test. Result: 1. The patients in the experimental group placed in semi fowler's position showed significant higher post-recovery scores than those in the control group who were in a supine position. 2. The patients in the experimental group who were in semi Fowler's position showed no significant higher $O_2$ saturation degree than those in the control group who were in supine position. Conclusion: Based on the results described above, it is considered that the semi-Fowler's position might be effective in enhancing the post-operative recovery score of the patients with laparoscopic abdominal surgery in recovery room.

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Battery Lifetime Enhancement Based on Recovery Effect (회복효과에 기반한 배터리 사용 시간 연장 기법)

  • Lee, Jong-Bae;Lee, Seongsoo
    • Journal of IKEEE
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    • v.18 no.1
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    • pp.96-105
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    • 2014
  • This paper proposes a battery lifetime enhancement method based on the nonlinear discharge charisteristics called recovery effect. In general, the stored energy in a battery is considered in the prediction of battery lifetime. However, due to the chemical reaction in a battery, more energy can be drawn from a battery when it is not continuously but intermittently discharged, which is called recovery effect. In the proposed method, several battery cells are alternately discharged, and some battery cells rest while maintaining the system power supply. This makes recovery effect of battery cells, which extends battery lifetime. In the experiment, battery lifetime increases about 7% in the alternating discharge of two battery cells, when compared with conventional parallel discharge.

The Current Evaluation State of Post-Anesthetic Recovery after General Anesthesia (전신마취 후 회복 평가도구 활용 실태)

  • Lee, Hwa In
    • Korean Journal of Adult Nursing
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    • v.18 no.5
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    • pp.691-698
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    • 2006
  • Purpose: This research was conducted to evaluate, analyze, and determine the limitation of the anesthesia that is used in there covery room in order to provide the foundation for developing the effectiveness of it. Method: There covery records of this study were collected from 41 hospitals in Seoul, Kyung Kii-Do, and Inchon province. The post anesthetic recovery records consisted of the evaluation of type, evaluative items, frequency, time, score and $SaO_2$. These records were collected from September to December of 2005. Results: The most commonly used post anesthetic evaluation tool was Alderete Score, which was used in 73% of hospitals. The second was Aldrete Score with $SaO_2$(17%). Also, 5% of the hospitals used the modified AS form. There were 2.5% of the hospitals applying the adult and child in the evaluation separately. Also, the last 2.5% of the hospitals did not use AS but measured BP, pulse, respiration, temperature, and $SaO_2$ with observing nausea, vomiting, urinary retention, backache, laryngitis, shock, and neurologic assessment. Conclusion: It is necessary to develop a post-anesthetic recovery evaluation tool including the application of $SaO_2$, so that the early-diagnosis of hypoxia can be possible. In addition, it is necessary to develop a post- anesthetic recovery evaluating method that can distinguish a difference between adults and children.

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Majorization-Minimization-Based Sparse Signal Recovery Method Using Prior Support and Amplitude Information for the Estimation of Time-varying Sparse Channels

  • Wang, Chen;Fang, Yong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.10
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    • pp.4835-4855
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    • 2018
  • In this paper, we study the sparse signal recovery that uses information of both support and amplitude of the sparse signal. A convergent iterative algorithm for sparse signal recovery is developed using Majorization-Minimization-based Non-convex Optimization (MM-NcO). Furthermore, it is shown that, typically, the sparse signals that are recovered using the proposed iterative algorithm are not globally optimal and the performance of the iterative algorithm depends on the initial point. Therefore, a modified MM-NcO-based iterative algorithm is developed that uses prior information of both support and amplitude of the sparse signal to enhance recovery performance. Finally, the modified MM-NcO-based iterative algorithm is used to estimate the time-varying sparse wireless channels with temporal correlation. The numerical results show that the new algorithm performs better than related algorithms.

An Analytical Method on the Effective Energy Recovery for Heat Exchanger with Heat Pipes (히이트 파이프용 열교환기의 에너지 회수효과 해석 해법)

  • Jang, Yeong-Suk;Seo, Hae-Sung;Lee, Young-Soo;Jun, Chul-Ho
    • Solar Energy
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    • v.9 no.2
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    • pp.31-41
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    • 1989
  • The purpose of this research is to study the utility of prediction program like a F.E.M. analysis for energy recovery of heat exchanger with heat pipe which uses arbitrary groove wick. The program is based on the utility by the experimental and applytical method of the single heat pipe. It is also expanded and applied in the prediction program of the heat exchanger. The results are as follows; 1) The effective thermal conductivity of the groove wick with arbitrary shape is counted by the thermal resistance change. 2) The more the number of rows, the more the effect energy recovery changing by the number of rows, the bigger the free velocity, the smaller the effect of energy recovery. 3) The effect of energy recovery increases according to the value of the rate of mass flow (Me/Mc) and also number of rows. 4) The comparison between calculated and data shows good agreement within 2.5% error, therefore the F.E.M. analysis of the study is useful to predict the performance of heat pipe-heat exchanger.

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Detection and Recovery of Failure Node in SAN-based Cluster Shared File System $SANique^{TM}$ (SAN 기반 클러스터 공유 파일 시스템 $SANique^{TM}$의 오류 노드 탐지 및 회복 기법)

  • Lee, Kyu-Woong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.12
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    • pp.2609-2617
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    • 2009
  • This paper describes the design overview of shared file system $SANique^{TM}$ and proposes the method for detection of failure node and recovery management algorithm. We also illustrate the characteristics and system architecture of shared file system based on SAN. In order to provide uninterrupted service, the detection and recovery methods are proposed under the all possible system failures and natural disasters. The various kinds of system failures and disasters are characterized and then the detection and recovery method are proposed in each disconnected computing node group.