• Title/Summary/Keyword: time-dependent effect

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Combined Effects of Sustained Load and Temperature on Pull-off Strength and Creep Response between CFRP Sheet and Concrete Using Digital Image Processing (디지털 이미지 분석을 통한 지속 하중과 온도의 복합 환경이 CFRP 쉬트와 콘크리트의 부착강도 및 크리프 거동에 미치는 영향 분석)

  • Jeong, Yo-Seok;Lee, Jae-Ha;Kim, Woo-Seok
    • Journal of the Korea Concrete Institute
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    • v.28 no.5
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    • pp.535-544
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    • 2016
  • This paper aims at examining the effects of sustained load and elevated temperature on the time-dependent deformation of a carbon fiber reinforced polymer (CFRP) sheets bonded to concrete as well as the pull-off strength of single-lap shear specimens after the sustained loading period using digital images. Elevated temperature during the sustained loading period resulted in increased slip of the CFRP composites, whereas increased curing time of the polymer resin prior to the sustained loading period resulted in reduced slip. Pull-off tests conducted after sustained loading period showed that the presence of sustained load resulted in increased pull-off strength and interfacial fracture energy. This beneficial effect decreased with increased creep duration. Based on analysis of digital images, results on strain distributions and fracture surfaces indicated that stress relaxation of the epoxy occurred in the 30 mm closest to the loaded end of the CFRP composites during sustained loading, which increased the pull-off strength provided the failure locus remained mostly in the concrete. For longer sustained loading duration, the failure mode of concrete-CFRP bond region can change from a cohesive failure in the concrete to an interfacial failure along the concrete/epoxy interface, which diminished part of the strength increase due to the stress relaxation of the adhesive.

Comparative study on stability and efficacy of Banhasasim-tang decoction depending on the preservation temperature and periods (반하사심탕 전탕액의 보관 온도 및 기간에 따른 안정성 및 유효성 연구)

  • Jin, Seong Eun;Kim, Ohn Soon;Seo, Chang-Seob;Shin, Hyeun-Kyoo;Jeong, Soo-Jin
    • The Journal of Korean Medicine
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    • v.37 no.1
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    • pp.21-33
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    • 2016
  • This study aimed to investigate the stability and biological activities of BHSST decoction depending on the preservation temperature and periods. Methods: BHSST decoction was preserved at room temperatures (R/T, $23{\pm}1^{\circ}C$) or refrigeration ($4^{\circ}C$) for 0, 30, 60 and 90 days. To evaluate the stability of BHSST decoction, pH and sugar content were estimated. In addition, high-performance liquid chromatography (HPLC) analysis was performed to determine marker compounds of BHSST decoction. To evaluate anti-inflammatory effect, nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) productions were measured in LPS-stimulated RAW 264.7 macrophages. Antioxidant activity was examined using the assays for 3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and 1-1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities. Results: There was no change in pH and sugar content depending on the preservation temperature and periods of BHSST decoction. Among the major components of BHSST, contents of liquiritin, baicalein and wogonin was reduced time-dependently both at R/T and $4^{\circ}C$. Inhibitory effects of BHSST decoction on NO and PGE2 productions were slightly decreased in a time-dependent manner by 90 days of preservation. In addition, BHSST decoction maintained ABTS and DPPH radical scavenging activities by 60 days while significantly reducing the activities in 90 days of preservation at R/T. By contrast, BHSST decoction had no significant change of ABTS and DPPH radical scavenging activities by 90 days at $4^{\circ}C$. Conclusions: Our results suggest that the stability and efficacy of BHSST decoction are maintained for 60 days at $4^{\circ}C$ rather than R/T.

Effects of Intraperitoneal Bupivacaine Instillation on Postoperative Pain Behavior after Laparoscopic Ovariohysterectomy in Dogs (개에서 복강경을 이용한 난소자궁절제술시 복강 내 Bupivacaine의 점적투여가 술 후 통증행동에 미치는 영향)

  • Kim, Young-Ki;Lee, Seung-Yong;Park, Se-Jin;Lee, Scott-S.;Suh, Euy-Hoon;Chang, Hong-Hee;Lee, Hee-Chun;Lee, Hyo-Jong;Yeon, Seong-Chan
    • Journal of Veterinary Clinics
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    • v.28 no.1
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    • pp.33-39
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    • 2011
  • The present study was aimed to investigate the effect of intraperitoneal bupivacaine instillation on postoperative pain after laparoscopic ovariohysterectomy (LOHE) in dogs. Twelve female German shepherd dogs (17-30 kg) were divided into two groups. The treatment group received 4.4 mg/kg of instilled intraperitoneal bupivacaine diluted to 0.25% with an equivalent volume of saline after pneumoperitoneum, but the control group received 1.76 ml/kg of 0.9% saline. Two blind observers measured the extent of dog's pain and sedation by using dynamic interactive visual analogue scale (DIVAS) preoperatively and 0.5, 1, 2, 4, 6, and 12 h postoperatively. At each designated time, blood cortisol, glucose, and creatine kinase (CK) concentrations were also measured. Based on the repeated-measures ANOVA, there were significant differences in time-dependent postoperative changes in patterns of DIVAS-pain score between two groups. In addition, the treatment group had significantly lower DIVAS-pain scores at 1, 2, 4, and 6 h postoperatively compared to the control group. DIVAS-sedation score and biochemical measures including cortisol, glucose, and CK did not show any significant differences between two groups. No complications associated with bupivacaine administration were observed. Thus, instilled bupivacaine intraperitoneally may be an effective method on relieving behavioral expressions associated with postoperative pain after laparoscopic ovariohysterectomy in dogs.

Development of the Power Monitoring System for the Planetary Geared Motor using Hall Effect Sensor (홀 이펙트 센서를 이용한 유성기어 감속기모터의 동력 모니터링 시스템 개발)

  • Jang, In-Hun;Sim, Kwee-Bo;Oh, Se-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.7
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    • pp.914-919
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    • 2004
  • When the motor is rotating, the torque and rpm are varying as the loads or the driving status connecting through reduction units are changing. On the contrary, one can monitor the changes of the loads or the driving status in the manner of measuring motor torque and rpm. There is a torque measuring method using the strain gauge and bridge circuit. But, because this is the contact method, it has the life time which is dependent on rotating velocity and used time. So this system demands on replacement of some Parts or whole system itself for maintenance. And this system is also relatively big and expensive, requiring preceding annoying process. In this paper, we are going to suppose non-contact method to measure torque and rpm using the Hall effects sensor For this we have made the planetary geared reduction motor with Hall sensors and with the monitoring system. The monitoring system displays the sensing data(torque, rpm) and calculated data( power) and also has the network capability with Bluetooth protocol. Our solution is much more inexpensive ;md simple method to measure torque and rpm than before.

Tissue Distribution and Toxicokinetics of 4-Tert-Octylphenol in Rats (4-Tert-Octylphenol의 랫드에서의 조직분포 및 독성동태에 관한 연구)

  • Kang Mi Kyung;Ahn Mee Ryung;Chung Hye Joo;Choi Sun Ok;Choi Hong Serk;Yang Ji Sun;Lee Yong Bok;Yoo Tae Moo;Sohn Soo Jung
    • Toxicological Research
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    • v.20 no.3
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    • pp.195-203
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    • 2004
  • 4-Tert-Octylphenol (OP) is a surfactant additive widely used in the manufacture of a variety of detergents and plastic products. OP can disrupt endocrine function in humans and animals. This study was carried out to obtain toxicokinetic parameters of OP in male Sprague-Dawley (SD) rats. Male rats were administered with OP by single oral application of 200 mg/kg body weight. Blood, urine and tissues samples were taken at several time intervals after administration. Analysis of samples for OP was performed by column-switching high performance liquid chromatography (HPLC). In addition, we exam-ined tissue distribution and accumulation of OP after single oral application of 50, 100, and 200 mg/kg, single intravenous injection of 1, 5 and 10 mg/kg or daily application of 50 mg/kg for 14 consecutive days. After single oral administration of 200 mg/kg, Cmax of 213 $\pm$ 123 ng/ml was reached within the first 1.3 hr (Tmax) in the plasma. AUC was calculated for 1,333$\pm$484 ngㆍhr/ml. The final elimination half-life of plasma was longer than that of urine, but urinary clearance was lower than oral. A very small fraction of OP (Fe < 0.0017%) was excreted in urine within 24 hr. These results indicated that the major excretion route of OP was not urine. The mean maximal tissue distribution of OP was obserbed at 6 hr after treatment and slowly decreased time-dependently. High OP concentrations were detected in fat at 24 hr. The OP in fat was slowly released with longer elimination half-life and lower clearance than that of other tissues. OP was not accumulated in the liver following single oral application but 14-day oral treatments resulted in two-fold accumulation. It was probably due to the saturation of detoxification pathways. On the other hand, the mRNA expression of cytochrome P450 isoforms except CYP2C11 was not affected by OP at any dose. The expression of CYP2C11 mRNA decreased in a dose-dependent manner. This result suggests that OP changes expression of the male-specific cytochrome P450 isoforms in rat liver, and these changes are closely related to the toxic and estrogenic effect of OP.

Baicalin Induces Apoptosis in Leukemia HL-60/ADR Cells via Possible Down-regulation of the PI3K/Akt Signaling Pathway

  • Zheng, Jing;Hu, Jian-Da;Chen, Ying-Yu;Chen, Bu-Yuan;Huang, Yi;Zheng, Zhi Hong;Liu, Ting-Bo
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1119-1124
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    • 2012
  • Background: The effect and possible mechanism of traditional Chinese medicine, baicalin, on the PI3K/Akt signaling pathway in drug-resistant human myeloid leukemia HL-60/ADR cells have been investigated in this current study. Methods: HL-60/ADR cells were treated by 20, 40, $80\;{\mu}mol/L$ baicalin followed by cell cycle analysis at 24h. The mRNA expression level of the apoptosis related gene, Bcl-2 and bad, were measured by RT-PCR on cells treated with $80\;{\mu}mol/L$ baicalin at 12, 24 and 48hr. Western blot was performed to detect the changes in the expression of the proteins related to HL-60/ADR cell apoptosis and the signaling pathway before and after baicalin treatment, including Bcl-2, PARP, Bad, Caspase 3, Akt, p-Akt, NF-${\kappa}B$, p-NF-${\kappa}B$, mTOR and p-mTOR. Results: Sub-G1 peak of HL-60/ADR cells appeared 24 h after $20\;{\mu}mol/L$ baicalin treatment, and the ratio increased as baicalin concentration increased. Cell cycle analysis showed 44.9% G0/G1 phase cells 24 h after baicalin treatment compared to 39.6% in the control group. Cells treated with $80\;{\mu}mol/L$ baicalin displayed a trend in decreasing of Bcl-2 mRNA expression over time. Expression level of the Bcl-2 and PARP proteins decreased significantly while that of the PARP, Caspase-3, and Bad proteins gradually increased. No significant difference in Akt expression was observed between treated and the control groups. However, the expression levels of p-Akt, NF-${\kappa}B$, p-NF-${\kappa}B$, mTOR and p-mTOR decreased significantly in a time-dependent manner. Conclusions: We conclude that baicalin may induce HL-60/ADR cell apoptosis through the PI3K/AKT signaling pathway.

Model Testing on the Behavior of Laterally Loaded Pile in NC Clay Soils (정규압밀 점토 지반에서 매입말뚝의 수평거동에 관한 모형 실험 연구)

  • Kim, Byeong-Tak;Lee, Sang-Ung;Kim, Yeong-Su
    • Geotechnical Engineering
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    • v.14 no.5
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    • pp.39-52
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    • 1998
  • The pupose of the present paper is to estimate the effects of constraint condition of pile head, ground condition(dry unit weight. $\gamma_4$) and embedded pile lengths on the behavior of single pile which is embedded in normally consolidated clay. BBperiment functions can be quantified to these effects obtained from the results of model teats. The ground of model tests is normally consolidated( NC ) clay under three kinds of effective vertical stress. The results of the model tests using the steel pile of two different embedded pile length and of free-head and fired-head show that the lateral load-deflection relationship is to be elasto plastic behavior below $\gamma_d/\gamma_{dmax}$: 0.84 and that the reduction of lateral load of beyond maximum lateral load($Q_{max}$) at each model test is significantly time-dependent. In this study, it is shown that the displacement relationship can be fitted to exponential function of time by model best results. The effect of ground conditions on the ultimate and yield lateral load is fitted to exponential function including the ratio of dry unit weight to maximum dry unit weight. When tests by results are compared with those from Broms and Budhu et at., the predicted results are over-estimated about 27-87 ayo. In effectivity of constraint condition of pile head on the lateral load-deflection response, the $Q_{fixed}/Q_{gree}-y/D$ relationship is highly non-linear and fitted to parabolic function.

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Adverse Effects of Chloral Hydrate in Neonates: Frequency and Related Factors (신생아에서 Chloral Hydrate의 부작용의 빈도와 관련 인자)

  • Lee, Ju-Young;Youn, Young-Ah;Kim, Soon-Ju;Lee, Hyun-Seung;Kim, So- Young;Sung, In-Kyung;Chun, Chung-Sik
    • Neonatal Medicine
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    • v.18 no.1
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    • pp.130-136
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    • 2011
  • Purpose: Chloral hydrate is a common drug frequently used for procedural sedation. But data on chloral hydrate use in the newborns are limited. This study examined the frequency of adverse effects of chloral hydrate and factors related to the adverse effects. We also examined if there were additional adverse effects when an additional sedative was used. Methods: The medical records of 104 patients admitted to neonatal intensive care unit of Seoul St. Mary's Hospital from March 2010 to February 2011 who used chloral hydrate for procedural sedation were retrospectively reviewed. Results: Adverse effects after administration of chloral hydrate were noted in 41.3% of the 104 patients. The adverse events included oxygen desaturation (18.8%), increase in apneic episodes (17.5%), increase in bradycardia (10%), and feeding intolerance (3.8%). Using oxygen at the time of chloral hydrate administration was independently associated with adverse effects (odds ratio [OR], 10.911: 95% confidence interval [CI], 2.082-57.178) and with the necessity for an additional sedative after administration of chloral hydrate (OR, 4.151: 95% CI, 1.455-11.840). Using one additional sedative agent after chloral hydrate showed no difference in adverse effects except feeding intolerance. Conclusion: Patients dependent on oxygen at the time of chloral hydrate administration may were found to be at higher risk for adverse effect of chloral hydrate and for an additional sedative. When an additional sedative is needed, it could be used with monitoring feeding intolerance after chloral hydrate administration.

The Development of Travel Demand Nowcasting Model Based on Travelers' Attention: Focusing on Web Search Traffic Information (여행자 관심 기반 스마트 여행 수요 예측 모형 개발: 웹검색 트래픽 정보를 중심으로)

  • Park, Do-Hyung
    • The Journal of Information Systems
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    • v.26 no.3
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    • pp.171-185
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    • 2017
  • Purpose Recently, there has been an increase in attempts to analyze social phenomena, consumption trends, and consumption behavior through a vast amount of customer data such as web search traffic information and social buzz information in various fields such as flu prediction and real estate price prediction. Internet portal service providers such as google and naver are disclosing web search traffic information of online users as services such as google trends and naver trends. Academic and industry are paying attention to research on information search behavior and utilization of online users based on the web search traffic information. Although there are many studies predicting social phenomena, consumption trends, political polls, etc. based on web search traffic information, it is hard to find the research to explain and predict tourism demand and establish tourism policy using it. In this study, we try to use web search traffic information to explain the tourism demand for major cities in Gangwon-do, the representative tourist area in Korea, and to develop a nowcasting model for the demand. Design/methodology/approach In the first step, the literature review on travel demand and web search traffic was conducted in parallel in two directions. In the second stage, we conducted a qualitative research to confirm the information retrieval behavior of the traveler. In the next step, we extracted the representative tourist cities of Gangwon-do and confirmed which keywords were used for the search. In the fourth step, we collected tourist demand data to be used as a dependent variable and collected web search traffic information of each keyword to be used as an independent variable. In the fifth step, we set up a time series benchmark model, and added the web search traffic information to this model to confirm whether the prediction model improved. In the last stage, we analyze the prediction models that are finally selected as optimal and confirm whether the influence of the keywords on the prediction of travel demand. Findings This study has developed a tourism demand forecasting model of Gangwon-do, a representative tourist destination in Korea, by expanding and applying web search traffic information to tourism demand forecasting. We compared the existing time series model with the benchmarking model and confirmed the superiority of the proposed model. In addition, this study also confirms that web search traffic information has a positive correlation with travel demand and precedes it by one or two months, thereby asserting its suitability as a prediction model. Furthermore, by deriving search keywords that have a significant effect on tourism demand forecast for each city, representative characteristics of each region can be selected.

A Study on the Profitability of the Commercial Bank in Terms of Interest Rate Marketization : Based on FMOLS Model (FMOLS 모형을 이용한 상업은행 수익성에 대한 연구 : 금리 시장화의 시각에서)

  • He, Yugang
    • The Journal of Industrial Distribution & Business
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    • v.9 no.8
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    • pp.41-50
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    • 2018
  • Purpose - As an important participant in the financial markets, the commercial bank will be impacted by the interest rate marketization. Owing to the special condition of China, this paper tries to explore the impact of operating mechanisms between interest rate marketization and the profitability of the commercial Bank. Research design, data and methodology - This paper applies time series data from 2005 to 2016. Due to the short period of time series, autocorrelation often occurs. Therefore, the fully modified least squares(FMOLS) will be used to conduct an empirical analysis. The reason is that it can move off the autocorrelation between variables and disturbance term. And FMOLS also can make estimated cointegrating parameters closed to normal distribution. More importantly, in order to avoid spurious regressions, the Augmented Dickey-Fuller Test will be used to verify the stationarity of all variables. The total return of asset is treated as the profitability of commercial bank. The net interest spread is treated as a measurement of interest rate marketization. Both are regarded as dependent variables. The non-interest income or gross revenues and impaired loans or gross loans are treated as independent variables. The sixteen representative listed commercial banks are divided into three categories (state-owned, share-holding and city-owned) to conduct an estimation. Results - Via empirical analysis, the findings show that the net interest spread has a positive effect on the profitability of the commercial bank. More specifically, 1% increase in the net interest spread will lead 0.157% increase in the profitability of state-owned commercial bank, 0.269% increase in the profitability of share-holding commercial bank and 0.263% increase in the profitability of city-owned commercial bank. If regarding the sixteen listed commercial city as a whole, 1% increase in the net interest spread will lead 0.267% increase in the profitability of the commercial bank. Conclusions - As the interest rate marketization, the importance of interest rate on the profitability of commercial bank has become more and more significant. The empirical evidences also prove that the net interest spread can bring about the change of the commercial bank's profitability. Therefore, policy-makers of commercial banks should fully understand the operating mechanism between them.