• International Journal of Aeronautical and Space Sciences
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• 제18권4호
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• pp.651-661
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• 2017

A truss-braced wing (TBW) aircraft has recently received increasing attention due to higher aerodynamic efficiency compared to conventional cantilever wing aircraft. For conceptual TBW aircraft design, we developed a propulsion-and-airframe integrated design environment by replacing a semi-empirical turbofan engine model with a thermodynamic cycle-based one built upon the numerical propulsion system simulation (NPSS). The constructed NPSS model benefitted TBW aircraft design study, as it could handle engine installation effects influencing engine fuel efficiency. The NPSS model also contributed to broadening TBW aircraft design space, for it provided turbofan engine design variables involving a technology factor reflecting progress in propulsion technology. To effectively consolidate the NPSS propulsion model with the TBW airframe model, we devised a rapid, approximate substitute of the NPSS model by reduced-order modeling (ROM) to resolve difficulties in model integration. In addition, we formed an artificial neural network (ANN) that associates engine component attributes evaluated by object-oriented weight analysis of turbine engine (WATE++) with engine design variables to determine engine weight and size, both of which bring together the propulsion and airframe system models. Through propulsion-andairframe design space exploration, we optimized TBW aircraft design for fuel saving and revealed that a simple engine model neglecting engine installation effects may overestimate TBW aircraft performance.

• Journal of Nutrition and Health
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• 제56권4호
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• pp.377-390
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• 2023

본 연구는 한국인을 대상으로 제2형 당뇨병 환자와 질병이 없는 정상대조군을 비교하여 성별에 따른 체액 불균형 정도와 영양소 섭취량을 평가하고자 하였다. 조사대상자는 총 57명으로, T2DM이 있는 T2DM군 (n = 36)과 T2DM이 없는 정상대조군 (n = 21)으로 나누어 분석하고, 성별에 따른 체액량의 차이를 고려하여 남성 T2DM군 (n = 24), 남성 정상대조군 (n = 9), 여성 T2DM군 (n = 12), 여성 정상대조군 (n = 12)으로 세분화하여 지표들의 특징을 분석하였다. BIA를 통하여 연구대상자의 체액 조성을 분석한 결과, ECW/ICW는 T2DM군이 정상대조군보다 유의적으로 높았고, 부종지수를 나타내는 ECW/TBW는 T2DM군이 정상대조군보다 유의적으로 높게 나타났다. 성별에 따른 체액 조성을 분석한 결과, 남성과 여성 모두 T2DM군은 정상대조군보다 높은 ECW/ICW, ECW/TBW를 보이며 동일한 체수분율 양상이 나타났다. 식사일기를 통해 연구대상자의 영양소 섭취량을 분석한 결과, 1,000 kcal 당 탄수화물, 식이섬유, 비타민 A, 비타민 C, 나트륨, 칼륨 섭취량은 T2DM군이 정상대조군보다 많았고, 1,000 kcal 당 지방, 콜레스테롤 섭취량은 T2DM군이 정상대조군보다 적었다. 본 연구를 통해 T2DM 환자에게서 체액 불균형이 나타날 가능성이 높음을 알 수 있었으며 추후 당뇨 합병증의 평가, 진단의 기초 자료로 널리 활용될 것으로 사료된다.

• Kidney Research and Clinical Practice
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• 제37권4호
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• pp.393-403
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• 2018

Background: This study compared nutritional parameters in hemodialysis (HD) subjects and controls using bioimpedance analysis (BIA) and investigated how BIA components changed before and after HD. Methods: This cross-sectional study included 147 subjects on maintenance HD from two hospitals and 298 propensity score-matched controls from one healthcare center. BIA was performed pre- and post-HD at mid-week dialysis sessions. Results: Extracellular water/total body water (ECW/TBW) and waist-hip ratio were higher in the HD patients; the other variables were higher in the control group. The cardiothoracic ratio correlated best with overhydration (r = 0.425, P < 0.01) in HD subjects. Blood pressure, hemoglobin, creatinine, and uric acid positively correlated with the lean tissue index in controls; however, most of these nutritional markers did not show significant correlations in HD subjects. Normal hydrated weight was predicted to be higher in the pre-HD than post-HD measurements. Predicted ultrafiltration (UF) volume difference based on pre- and post-HD ECW/TBW and measured UF volume difference showed a close correlation ($r^2=0.924$, P < 0.01). Remarkably, the leg phase angle increased in the post-HD period. Conclusion: The estimated normal hydrated weight using ECW/TBW can be a good marker for determining dry weight. HD subjects had higher ECW/TBW but most nutritional indices were inferior to those of controls. It was possible to predict UF volume differences using BIA, but the post-HD increase in leg phase angle, a nutritional marker, must be interpreted with caution.

• Korean Journal of Radiology
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• 제19권6호
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• pp.1021-1030
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• 2018

Objective: We evaluated the effect of various patient characteristics and time-density curve (TDC)-factors on the test bolus-affected vessel enhancement on coronary computed tomography angiography (CCTA). We also assessed the value of generalized linear regression models (GLMs) for predicting enhancement on CCTA. Materials and Methods: We performed univariate and multivariate regression analysis to evaluate the effect of patient characteristics and to compare contrast enhancement per gram of iodine on test bolus (${\Delta}HUTEST$) and CCTA (${\Delta}HUCCTA$). We developed GLMs to predict ${\Delta}HUCCTA$. GLMs including independent variables were validated with 6-fold cross-validation using the correlation coefficient and Bland-Altman analysis. Results: In multivariate analysis, only total body weight (TBW) and ${\Delta}HUTEST$ maintained their independent predictive value (p < 0.001). In validation analysis, the highest correlation coefficient between ${\Delta}HUCCTA$ and the prediction values was seen in the GLM (r = 0.75), followed by TDC (r = 0.69) and TBW (r = 0.62). The lowest Bland-Altman limit of agreement was observed with GLM-3 (mean difference, $-0.0{\pm}5.1$ Hounsfield units/grams of iodine [HU/gI]; 95% confidence interval [CI], -10.1, 10.1), followed by ${\Delta}HUCCTA$ ($-0.0{\pm}5.9HU/gI$; 95% CI, -11.9, 11.9) and TBW ($1.1{\pm}6.2HU/gI$; 95% CI, -11.2, 13.4). Conclusion: We demonstrated that the patient's TBW and ${\Delta}HUTEST$ significantly affected contrast enhancement on CCTA images and that the combined use of clinical information and test bolus results is useful for predicting aortic enhancement.

• Journal of Trauma and Injury
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• 제29권1호
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• pp.22-27
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• 2016

Purpose: The optimal method of fixation of symphysis pubis (SP) diastasis in pelvic ring injuries is still controversial. In this study, we investigated the radiological and the clinical results of a precontoured 4.5-mm symphysis pubis (SP) plate with tension band wiring (TBW) after an anterior pelvic injury in pelvic fractures. Methods: We treated 25 patients with traumatic SP diastasis by open reduction and internal fixation with plates and wires. We used a four-hole 4.5-mm precontoured SP plate with a tension band wiring. Results: Patients with a SP with TBW fixation achieved excellent or good results at final follow-up. Post-operative complications included two (8%) patients with metal work movement. The mean symphyseal width was smaller in 4.5 mm SP plate with TBW during 1-year follow up period. Conclusion: A precontoured symphysis pubis plate (4.5 mm) with figure-of-eight fashion tension band wiring shows favorable radiological results, excellent or good clinical outcome, and a lower complication (hardware failure and revision surgery).

• The Korean Journal of Medicine
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• 제93권6호
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• pp.548-555
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• 2018

목적: 혈액투석 환자에서 체수분 상태는 중요한데 혈액투석 이후의 과수분 상태는 고혈압, 부종, 심혈관계 합병증을 유발할 수 있다. 혈액투석 환자의 근육량 평가 및 체수분 상태를 측정할 수 있는 BIA 검사를 이용하여 혈액투석 환자에서 이환율, 생존율과 관련된 인자를 알아보고자 하였다. 방법: 본 연구는 후향적 연구로 2010년 1월부터 2015년 5월 30일까지 BIA를 측정한 말기 신부전으로 진단받고 투석을 3개월 이상 시행한 환자를 대상으로 하였으며, 2017년 6월 30일까지 추적 관찰하였다. 혈액투석 환자에서 시행하는 기본 혈액 검사와 BIA data (ECW, ICW, TBW, SLM, FFM, SMM 등)를 참조하여 환자의 이환율, 생존율 등을 분석하였다. 결과: 사망군과 생존군에서 SLM, SMM, FFM의 차이는 없었다. 생존군에서 사망군보다 나이, C-반응단백 수치가 낮았고, 혈청 알부민, 부갑상샘호르몬, 인이 높았으며, 총 체액량(TBW) 중 세포외액량(ECW)의 비율은 사망군에서 좀 더 높은 결과를 보였다($0.39{\pm}0.01$ vs. $0.40{\pm}0.01$; p < 0.05). 과수분군을 ECW/TBW ratio > 0.4로 정의하였을 때 Kaplan-Meier 생존분석에서 과수분군에서 통계적으로 유의하게 사망률이 높았다. 결론: 혈액투석 환자에서 BIA로 측정한 근육량 감소과 과수분 상태는 환자의 사망률과 이환율과 관련된 중요한 인자로 생각되며, 근육량 감소보다는 과수분 상태가 사망률과 좀 더 밀접한 관련이 있을 것으로 생각된다.

• 센서학회지
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• 제26권3호
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• pp.160-167
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• 2017

Many stroke patients undergoing rehabilitation therapy require a quantitative indicator for the evaluation of body composition in paretic and non-paretic regions. In this study, the body fluid alteration in the paretic and non-paretic regions of stroke patients with hemiplegia caused by cerebral hemorrhage and cerebral infarction was analyzed using bioelectrical impedance analysis (BIA). Alterations in body fluids were investigated to assess the physical status of the paretic and non-paretic regions of 20 stroke patients with hemiplegia caused by cerebral hemorrhage (7 patients) and cerebral infarction (13 patients). Extracellular water (ECW), intracellular water (ICW), ICW/ECW, total body water (TBW), ECW/TBW, and TBW/fat-free mass were utilized to evaluate the functional status of the paretic and non-paretic regions. Compared with the non-paretic region, the paretic region had high ECW and low ICW. Due to the loss of motor function and nutritional imbalance caused by the stroke, the amount of fat increased while the muscle quantity and quality significantly decreased in the paretic region. Thus, BIA can be a useful tool for quantitatively assessing paretic and non-paretic regions in stroke patients with hemiplegia.

• 대한물리치료과학회지
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• 제10권2호
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• pp.137-144
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• 2003

The purpose of this study was to investigate the difference of body composition of the elderly according to the age. This study consisted of elder male(n=48) and elder female(n=58). The average age of male elder and female elder was 73.81, 73.05 years. The data were analyzed with t-test, using SPSSWIN 10.1 program. Body composition was measured using Inbody 3.0(seoul, korea) of segmental multifrequency impedance analyzer technique. The result of this study were the following : 1. The difference of body composition according to the age 1) The MV(Muscle Volume)of male elder was significant difference among group(p<.05). The MV of female elder was very significant difference among group(p<.01). 2) The %FAT of male elder and female elder was no significant difference among group. 3) The FFM(Free Fat Mass)of male elder was significant difference among group(p<.05). The FFM of female elder was very significant difference among group(p<.01). 4) The TBW(Total Body Water)of male elder was significant difference among group(p<.05) The TBW of female elder was very significant difference among group(p<.01). 5) The WHR(Waist to Hip Ratio)of male elder was significant difference among group(p<.05). The WHR of female elder was very significant difference among group(p<.01).

• 자동차안전학회지
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• 제7권4호
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• pp.9-15
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• 2015

The relationship between BAC(Blood Alcohol Concentrations) and BrACs(Breath Alcohol Concentrations) and also partition ratio of healthy Korean adult males (96 males) are researched in this paper and its dependency is described according to TBW (total body water), BMI (body mass index), BFM (body fat mass), and PBF (percentage of body fat). Among the above four variables, TBW affects significantly to the partition ratio compared to the other variables. The partition ratio of Korean healthy males showed 1,913 (95 % Confidence Interval (C.I.) from 1,889 to 1,937) for the whole time intervals. However, when Q was averaged after 60 minutes later, its values was 2,011 (95 % C.I. from 1,982 to 2,040). Bland-Altman plots showed the compatibility of measurement methods of multi-gas analyzer, and the biases according to the partition ratios (Q=2,100 and Q=1,913) gave -0.0052 % (95 % CI from -0.0059 to -0.0045%) and -0.0004 % (95 % CI from -0.0011 to +0.0003%), respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제5권1호
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• pp.7-11
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• 1992

Body water compartments in vivo were determined in Holstein cattle with age ranging from 5 to 521 days to obtain an equation to estimate volumes of body water. Live weight ranged from 47 to 480 kg. Compartments were determined as antipyrine space for total body water (TBW), thiocyanate space for extracellular water (ECW) and Evans blue dye space for plasma water (PW). Body water compartments expressed as a percentage of live weight decreased as age in days increased and significantly correlated with age in days. Regression analyses revealed that prediction equations had low accuracy. Regression equations of body water compartments on live weight (WT, kg) were useful for the prediction of body fluid with a high accuracy. Live weight significantly regressed on age in days (Day), which was inferred to be utilized for estimation of standardized live weight in case animals were emaciated by certain causes such as severe diarrhea or dehydration. In conclusion, following equations were presented to estimate body water compartments of cattle in vivo : TBW in liters = $0.556({\pm}0.007)WT+10$, r = 0.993, $SE{\pm}0.7$ ECW in liters = $0.321({\pm}0.008)WT+10$, r = 0.978, $SE{\pm}0.8$ PW in liters = $0.0502({\pm}0.0012)WT+1.6$, r = 0.0983, $SE{\pm}0.1$ WT (kg) = $0.772({\pm}0.018)Day+24$, r = 0.982, $SE{\pm}2.3$.