• 제목/요약/키워드: center loss

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A simple and novel equation to estimate the degree of bleeding in haemorrhagic shock: mathematical derivation and preliminary in vivo validation

  • Chon, Sung-Bin;Lee, Min Ji;Oh, Won Sup;Park, Ye Jin;Kwon, Joon-Myoung;Kim, Kyuseok
    • The Korean Journal of Physiology and Pharmacology
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    • v.26 no.3
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    • pp.195-205
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    • 2022
  • Determining blood loss [100% - RBV (%)] is challenging in the management of haemorrhagic shock. We derived an equation estimating RBV (%) via serial haematocrits (Hct1, Hct2) by fixing infused crystalloid fluid volume (N) as [0.015 × body weight (g)]. Then, we validated it in vivo. Mathematically, the following estimation equation was derived: RBV (%) = 24k / [(Hct1 / Hct2) -1]. For validation, non-ongoing haemorrhagic shock was induced in Sprague-Dawley rats by withdrawing 20.0%-60.0% of their total blood volume (TBV) in 5.0% intervals (n = 9). Hct1 was checked after 10 min and normal saline N cc was infused over 10 min. Hct2 was checked five minutes later. We applied a linear equation to explain RBV (%) with 1 / [(Hct1 / Hct2) -1]. Seven rats losing 30.0%-60.0% of their TBV suffered shock persistently. For them, RBV (%) was updated as 5.67 / [(Hct1 / Hct2) -1] + 32.8 (95% confidence interval [CI] of the slope: 3.14-8.21, p = 0.002, R2 = 0.87). On a Bland-Altman plot, the difference between the estimated and actual RBV was 0.00 ± 4.03%; the 95% CIs of the limits of agreements were included within the pre-determined criterion of validation (< 20%). For rats suffering from persistent, non-ongoing haemorrhagic shock, we derived and validated a simple equation estimating RBV (%). This enables the calculation of blood loss via information on serial haematocrits under a fixed N. Clinical validation is required before utilisation for emergency care of haemorrhagic shock.

Effect of fermented sarco oyster extract on age induced sarcopenia muscle repair by modulating regulatory T cells

  • Kyung-A Byun;Seyeon Oh;Sosorburam Batsukh;Kyoung-Min Rheu;Bae-Jin Lee;Kuk Hui Son;Kyunghee Byun
    • Fisheries and Aquatic Sciences
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    • v.26 no.6
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    • pp.406-422
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    • 2023
  • Sarcopenia is an age-related, progressive skeletal muscle disorder involving the loss of muscle mass and strength. Previous studies have shown that γ-aminobutyric acid (GABA) from fermented oysters aids in regulatory T cells (Tregs) cell expansion and function by enhancing autophagy, and concomitantly mediate muscle regeneration by modulating muscle inflammation and satellite cell function. The fermentation process of oysters not only increases the GABA content but also enhances the content of branched amino acids and free amino acids that aid the level of protein absorption and muscle strength, mass, and repair. In this study, the effect of GABA-enriched fermented sarco oyster extract (FSO) on reduced muscle mass and functions via Treg modulation and enhanced autophagy in aged mice was investigated. Results showed that FSO enhanced the expression of autophagy markers (autophagy-related gene 5 [ATG5] and GABA receptor-associated protein [GABARAP]), forkhead box protein 3 (FoxP3) expression, and levels of anti-inflammatory cytokines (interleukin [IL]-10 and transforming growth factor [TGF]-β) secreted by Tregs while reducing pro-inflammatory cytokine levels (IL-17A and interferon [IFN]-γ). Furthermore, FSO increased the expression of IL-33 and its receptor IL-1 receptor-like 1 (ST2); well-known signaling pathways that increase amphiregulin (Areg) secretion and expression of myogenesis markers (myogenic factor 5, myoblast determination protein 1, and myogenin). Muscle mass and function were also enhanced via FSO. Overall, the current study suggests that FSO increased autophagy, which enhanced Treg accumulation and function, decreased muscle inflammation, and increased satellite cell function for muscle regeneration and therefore could decrease the loss of muscle mass and function with aging.

Ten technical aspects of baseplate fixation in reverse total shoulder arthroplasty for patients without glenoid bone loss: a systematic review

  • Reinier W.A. Spek;Lotje A. Hoogervorst;Rob C. Brink;Jan W. Schoones;Derek F.P. van Deurzen;Michel P.J. van den Bekerom
    • Clinics in Shoulder and Elbow
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    • v.27 no.1
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    • pp.88-107
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    • 2024
  • The aim of this systematic review was to collect evidence on the following 10 technical aspects of glenoid baseplate fixation in reverse total shoulder arthroplasty (rTSA): screw insertion angles; screw orientation; screw quantity; screw length; screw type; baseplate tilt; baseplate position; baseplate version and rotation; baseplate design; and anatomical safe zones. Five literature libraries were searched for eligible clinical, cadaver, biomechanical, virtual planning, and finite element analysis studies. Studies including patients >16 years old in which at least one of the ten abovementioned technical aspects was assessed were suitable for analysis. We excluded studies of patients with: glenoid bone loss; bony increased offset-reversed shoulder arthroplasty; rTSA with bone grafts; and augmented baseplates. Quality assessment was performed for each included study. Sixty-two studies were included, of which 41 were experimental studies (13 cadaver, 10 virtual planning, 11 biomechanical, and 7 finite element studies) and 21 were clinical studies (12 retrospective cohorts and 9 case-control studies). Overall, the quality of included studies was moderate or high. The majority of studies agreed upon the use of a divergent screw fixation pattern, fixation with four screws (to reduce micromotions), and inferior positioning in neutral or anteversion. A general consensus was not reached on the other technical aspects. Most surgical aspects of baseplate fixation can be decided without affecting fixation strength. There is not a single strategy that provides the best outcome. Therefore, guidelines should cover multiple surgical options that can achieve adequate baseplate fixation.

Tribological Failure Analysis of Automatic Transmission in a Passenger Car (승용차 자동변속기의 고장사례에 관한 트라이볼로지적 고찰)

  • Kim, Chung-Kyun;Lee, Il-Kwon
    • Tribology and Lubricants
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    • v.21 no.5
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    • pp.227-235
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    • 2005
  • This paper presents a tribological study on the failure cases of automatic transmission components in a passenger car. The automatic transmission system is composed of torque converter, clutch, brake, planetary gear, and valve body controlling oil pressure of an automatic transmission fluid. The most largest influence components in an automatic transmission are a torque converter and clutch plate in which are influenced by a wear and torque converting energy loss. The failure case study of an automatic transmission indicates that the tribological design and maintenance technologies should be considered as a key design concept. This means that the failure and power energy loss come from the friction, wear and a oil leakage of an automatic transmission, which is related to the oil seal and O-ring seal failures.

Spurious Suppressed Substrate Integrated Waveguide Bandpass Filter Using Stepped-Impedance Resonator

  • Lee, Il-Woo;Nam, Hee;Yun, Tae-Soon;Lee, Jong-Chul
    • Journal of electromagnetic engineering and science
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    • v.10 no.1
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    • pp.1-5
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    • 2010
  • A spurious suppressed bandpass filter is proposed and discussed using the stepped impedance resonator(SIR) on a substrate-integrated waveguide(SIW) structure with a double-layer substrate. The second resonance of the fundamental $TE_{10}$ mode can be controlled by adjusting the electrical length and impedance ratio of each SIR. The spurious suppressed SIW bandpass filter shows the measurement results of the insertion loss of 3.98 dB and return loss of less than 11.58 dB at the center frequency of 12 GHz. Also, the second spurious frequency is improved to about $1.5f_0$ compared with $1.33f_0$.

Power Sharing Method for a Grid connected Microgrid with Multiple Distributed Generators

  • Nguyen, Khanh-Loc;Won, Dong-Jun;Ahn, Seon-Ju;Chung, Il-Yop
    • Journal of Electrical Engineering and Technology
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    • v.7 no.4
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    • pp.459-467
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    • 2012
  • In this paper, a grid connected microgrid with multiple inverter-based distributed generators (DGs) is considered. DG in FFC mode regulates the microgrid as a controllable load from the utility point of view as long as its output is within the capacity limit. The transition mode causes a change in frequency of microgrid due to the loss of power transferred between main grid and microgrid. Frequency deviation from the nominal value can exceed the limit if the loss of power is large enough. This paper presents a coordinated control method for inverter-based DGs so that the microgrid is always regulated as a constant load from the utility viewpoint during grid connected mode, and the frequency deviation in the transition mode is minimized. DGs can share the load by changing their control modes between UPC and FFC and stabilize microgrid during transition.

A study on the apparel sizing system of adult women (성인여성 기성복의 치수 간격설정에 관한 연구)

  • 이진희;최혜선;박수찬;김진호
    • Journal of the Ergonomics Society of Korea
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    • v.13 no.1
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    • pp.59-74
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    • 1994
  • The purposes of this paper were to suggest the procedures for a sizing sys- tem which can provide good fitting of apparel and minimize the loss due to excessive inventory, and to determine an adequate apparel sizing standard. An anthropometric database used for this study was the 1992 National Anthro- pometric Survey of Koreans. The database was limited to 1,336 women who were 18-51 years old. They study was conducted by classifying ages into two groups (18-33, 34-51) using Wilk's lamda. Three principal components : laterality( fullness), linearity(length) and characteristic of torso were selected to describe body types, and these three body type classification of each group were selected by cluster analysis. It was found that all intervals between standard sizes were not equal. They were narrow around the center with high frequencies of the customers but wide in both tail with low frequencies. It was also found that the optimal sizes suing the loss function can be applied well in practice.

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Practical Bifurcation Criteria considering Inductive Power Pad Losses in Wireless Power Transfer Systems

  • Kim, Minkook;Lee, Jae-Woo;Lee, Byoung Kuk
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.173-181
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    • 2017
  • In this paper, the bifurcation criteria for inductive power transfer (IPT) systems is suggested considering the inductive power pad losses. The bifurcation criteria for series-series (SS) and series-parallel (SP) topologies are derived in terms of the main parameters of the IPT system. For deriving precise criteria, power pad resistance is obtained by copper loss calculation and core loss analysis. Utilizing the suggested criteria, possibility of bifurcation occurrence can be predicted in the design process. In order to verify the proposed criteria, 50 W IPT laboratory prototype is fabricated and the feasibilities of the switching frequency and AC load resistance shift to escape from bifurcation are identified.

Cycle Simulation for the Performance Prediction of a High Pressure Unit Injection System of a Diesel Engine (디젤엔진용 고압분사 유닛인젝터의 성능예측을 위한 사이클 시뮬레이션)

  • 김철호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.1
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    • pp.63-74
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    • 2001
  • In this study, a cycle simulation program of a Unit-Injection(UI) system was developed to estimate the injection performance of newly designed injection system. A fundamental theory of the simulation program is based on the conservation law of mass. Loss of fuel mass in the system due to leakage, compressibility effect of the liquid fuel and friction loss in the control volume was considered in the algorithm f the program. For the evaluation of the simulation program developed, the experimental result which was offered by the Technical Research Center of Doowon Precision Industry Co. was incorporated. Two main parameters; the maximum pressure in the plunger chamber and total fuel mass(kg) injected into the engine cylinder per cycle, were measured and compared with the simulation results. It was found that the maximum error rate of the simulation result to the experimental output was less than 3% in the rated rotational speed (rpm) range of the plunger cam.

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A Study on Feedforward System for IMT-2000

  • Jeon Joong-Sung
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.4
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    • pp.505-513
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    • 2006
  • A linear power amplifier is particularly emphasized on the system using a linear modulations, such as 16QAM and QPSK with pulse shaping. because intermodulation distortion which causes adjacent channel interference and co-channel interference is mostly generated in a nonlinear power amplifier. In this paper, parameters of a linearization loop, such as an amplitude imbalance a phase imbalance and a delay mismatch, are briefly analyzed to get a specific cancellation performance and linearization bandwidth. Experimental results are presented for IMT-2000 frequency band. The center frequency of the feedforward amplifier is 2140 MHz with 60 MHz bandwidth. When the average output power of feedforward amplifier is 20 Watt. the intermodulation cancellation performance is more than 21 dB. In this case, the output power of feedforward amplifier reduced 3.5 dB because of extra delay line loss and coupling loss. The feedforward amplifier efficiency is more than 7.2 % for multicarrier signals, 59 dBc for ACPR.