• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.271-272
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• 2015

Gas turbine combustors is critical part due to high temperature operating conditions and the optimization of cooling design is required to avoid combustor failure. In gas turbine combustor, effusion cooling, impingement cooling and thermal barrier coating (TBC) are commonly used to improve cooling characteristics. In conceptual design, these cooling schemes are designed by 1D heat transfer calculation. Therefore, these design should be validated ted by nemurical or experiment methods. In this study, Conjugate Heat Transfer (CHT) analysis is performed for validation of gas turbine combustor cooling design.

• CELLMED
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• v.1 no.1
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• pp.6.1-6.4
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• 2011

For cancer patients undergoing radiation therapy (RT) or systemic chemotherapy (CHT), cancer-related fatigue (CRF) is a common problem that can negatively impact their quality of life. Guarana (Paullinia cupana) is a plant native to the Amazon basin that has been used as a stimulant since pre-Columbian times. PURPOSE: To evaluate the effectiveness of guarana extract on fatigue in BC patients undergoing either CHT or RT. A total of 137 cancer patients (85% with Breast Cancer) undergoing either CHT (101) or RT (36) were randomized to receive either a placebo or guarana. In all 3 studies, the guarana was given as an unmanipulated dry extract at a dose of 75 mg PO QD in the first two studies or 50 mg PO BID in the third study. Patients were crossed over to the other experimental arm, and we evaluated fatigue with the Chalder Scale in all three studies. Guarana significantly improved the The Chalder Scale Global Scores (- 0.85; 95% CI:-1.31 to -0.40; p = 0.0002); Physical Fatigue Scores (-0.44; 95% CI: - 0.74 to - 0.13; p = 0.005) and Mental Fatigue Scores (-0.93; 95% CI: - 1.14 to - 0.72; p < 0.00001). Guarana did not produce any CTCAE grades 3 or 4 toxicities in any of the studies. Guarana is an effective, cheap and non-toxic alternative for the treatment of fatigue in cancer patients undergoing treatment.

• Earthquakes and Structures
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• v.17 no.6
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• pp.635-647
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• 2019

Tests and theoretical studies for seismic responses of a transmission tower-line system under coupled horizontal and tilt (CHT) ground motion were conducted. The method of obtaining the tilt component from seismic motion was based on comparisons from the Fourier spectrum of uncorrected seismic waves. The collected data were then applied in testing and theoretical analysis. Taking an actual transmission tower-line system as the prototype, shaking table tests of the scale model of a single transmission tower and towers-line systems under horizontal, tilt, and CHT ground motions were carried out. Dynamic equations under CHT ground motion were also derived. The additional P-∆ effect caused by tilt motion was considered as an equivalent horizontal lateral force, and it was added into the equations as the excitation. Test results were compared with the theoretical analysis and indicated some useful conclusions. First, the shaking table test results are consistent with the theoretical analysis from improved dynamic equations and proved its correctness. Second, the tilt component of ground motion has great influence on the seismic response of the transmission tower-line system, and the additional P-∆effect caused by the foundation tilt, not only increases the seismic response of the transmission tower-line system, but also leads to a remarkable asymmetric displacement effect. Third, for the tower-line system, transmission lines under ground motion weaken the horizontal displacement and acceleration responses of transmission towers. This weakening effect of transmission lines to the main structure, however, will be decreased with consideration of tilt component.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.1170-1182
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• 2023

The aim of this study was to determine the effect of chitosan (CH)-based nanocomposite coating applications [chitosan+TiO₂ (CHT) and chitosan+TiO₂+rosmarinic acid (CHTRA)] on changes in quality attributes of rainbow trout fillets during cold storage (4℃). Fish fillets were randomly divided into four groups and subjected to treatments (CH, CHT, CHTRA, and control). After treatments, the groups were packaged under a modified atmosphere (40% CO₂+30% O₂+30% N₂) and stored at 4℃ for 18 days. During cold storage, the samples were subjected to physico-chemical and microbiological analyses. During storage, CH, CHT, and CHTRA treatments showed lower aerobic mesophilic and psychrotrophic bacteria counts than the control. However, the differences between coating treatments were not significant. The highest mean pH value was determined in the control group. As the storage time increased, the thiobarbituric acid reactive substances value increased. At the end of the storage period, no significant differences were observed between the treatments, including in the control group. The total volatile basic nitrogen (TVB-N) level in the control group was above 25 mg/100 g on day 15 of storage. However, the TVB-N level in the treatment groups was below 20 mg/100 g on day 18. It was also determined that coating application×storage period interaction had a significant effect on all color parameters (p<0.01). At the end of storage, the highest CIE L* was observed in CHTRA treatment. However, the value of this treatment did not differ from that of the CH treatment.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.2
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• pp.279-289
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• 2017

In this study, a series of conjugate heat transfer (CHT) analyses are conducted for a stage of a fully cooled high-pressure turbine (HPT) at elevated levels of free stream turbulence (Tu = 5% and 25.7%). The goal of the analyses is to investigate the influence of high turbulence intensity on the fluid-thermal characteristics of a nozzle guide vane (NGV). The turbine inlet temperature is defined by considering a typical radial temperature distribution factor (RTDF). The Unsteady Reynolds Average Navier-Stokes (URANS) CHT simulations are carried out using CFX 15.0, a commercial CFD package. The presented CFD modeling approach for high turbulence intensity is verified with the experimental data from two types of NASA C3X NGVs with films. The computation grid is generated for both the fluid and solid domains. The fluid domain grid is created using a tetrahedral grid system with prism layers because of its complex geometry, and the solid domain grid is composed of only tetrahedral elements. The analytical results are compared to understand the effect of turbulence on flow characteristics and metal temperature distributions. The results obtained in this study provide useful insights on the effects of high free stream turbulence and unsteadiness. The results also lead to the proposal of meaningful turbine design guidelines.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.59-70
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• 2020

The purpose of this study is to construct the ACD model for the block trading volume duration. The ACD model based on the block trading volume duration is referred to as Volume ACD (VACD) in this study. By integrating with GARCH-type models, the VACD based GARCH type models, which include VACD-GARCH, VACD-IGARCH and VACD-FIGARCH models, are set up. This study selects Chunghwa Telecom (CHT) Inc., offering the America Depository Receipt (ADR) in NYSE, to investigate the block trading volume duration in Taiwanese equity market. The empirical results indicate that the long memory in volume duration series increases dependence at level of volatility clustering by VACD (2,1)-FIGARCH (3,d,1) model. Moreover, the VACD (2,1)-IGARCH (1,1) exhibits relatively better performance of prediction on capturing block trading volume duration. This volatility model is more appropriate in this study to portray the change of the CHT Inc. prices and provides more information about the volatility process for investment strategy, which can be a reference indicator of financial asset pricing, hedging strategy and risk management.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.4
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• pp.1013-1018
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• 2003

Cheonghunhwadam-tang(CHT) have been used in oriental medicine for many centuries as a therapeutic agent of vertigo by wind, fire and phlegm. CTG was CHT adding Aurantii FructusㆍGastrodae Rhizoma. CTG was significantly increased regional cerebral blood f1ow(rCBF) in a dose-dependent, and CTG was decreased mean arterial blood pressure(MABP) compared with normal MABP(100%) in a low dosage, but was increased MABP in a dose-dependent, was aliked with normal MABP in a high-dosage. Therefore, purpose of this Study was to investigate experimental mechanism of CHTAG on the cerebral hemodynamics(rCBF, MABP) in rats. The changes of rCBF and MABP were determinated by Laser-Doppler Flowmetry(LDF). The results were as follows ; Pretreatment with indomethacin(3㎎/㎏, i.v.) was significantly inhibited CTG induced increase of rCBF and pretreated with propranolol(3㎎/㎏, i.v.) was inhibited CTG induced increase of rCBF, but pretreatment with methylene blue(10㎍/㎏, i.v) was increased CTG induced increase of rCBF. Pretreatment with indomethacin was decreased CTG induced increase of MABP, but pretreatment with propranolol and methylene blue were increased CTG induced increase of MABP. This results suggest that the mechanism of CTG is mediated by cyclooxygenase.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.186-189
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• 1998

In this paper, we provide a mathematical formulation to describe the random mobility of users in cellular radio systems. With this, we can also study tile cell sojourn time (CST) distribution as well as the channel holding time (CHT) distribution. The study on user mobility enables to improve the resource management in cellular radio systems. We provide a versatile analysis tool that improves the limit of simplified analyses.

• Bulletin of the Korean Chemical Society
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• v.15 no.7
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• pp.599-602
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• 1994

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.11
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• pp.763-770
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• 2014

In traditional routing protocols including LEACH for wireless sensor networks, nodes suffer from unbalanced energy consumption because the nodes require large transmission energy as the distance to the sink node increase. Multi-hop based routing protocols have been studied to address this problem. In existing protocols, each cluster head usually chooses the closest head as a relay node. We propose LEACH-CHT, in which cluster heads choose the path with least energy consumption to send data to the sink node. In our research, each hop, a cluster head selects the least cost path to the sink node. This method solves the looping problem efficiently as well as make it possible that a cluster head excludes other cluster heads placed farther than its location from the path, without additional energy consumption. By balancing the energy consumption among the nodes, our proposed scheme outperforms existing multi-hop schemes by up to 36% in terms of average network lifetime.