• Journal of Cardiovascular Imaging
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• 제31권4호
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• pp.169-177
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• 2023

BACKGROUND: Acute worsening of cardiac function frequently leads to kidney dysfunction. This study aimed to identify clinical and imaging parameters associated with impaired kidney function in patients with acute decompensated heart failure with reduced ejection fraction (HFrEF). METHODS: Data from 131 patients hospitalized with acute decompensated HFrEF (left ventricular ejection fraction, < 40%) were analyzed. Patients were divided into two groups according to the glomerular filtration rate (GFR) at admission (those with preserved kidney function [GFR ≥ 60 mL/min/1.73 m²] and those with reduced kidney function [GFR < 60 mL/min/1.73 m²]). Various echocardiographic parameters and perirenal fat thicknesses were assessed by computed tomography. RESULTS: There were 71 patients with preserved kidney function and 60 patients with reduced kidney function. Increased age (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.04-1.12; p = 0.005), increased log N-terminal pro b-type natriuretic peptide (OR, 1.74; 95% CI, 1.14-2.66; p = 0.010), and increased perirenal fat thickness (OR, 1.19; 95% CI, 1.10-1.29; p < 0.001) were independently associated with reduced kidney function, even after adjusting for variable clinical and echocardiographic parameters. The optimal average perirenal fat thickness cut-off value of > 12 mm had a sensitivity of 55% and specificity of 83% for kidney dysfunction prediction. CONCLUSIONS: Thick perirenal fat was independently associated with impaired kidney function in patients hospitalized for acute decompensated HFrEF. Measurement of perirenal fat thickness may be a promising imaging marker for the detection of HFrEF patients who are more susceptible to kidney dysfunction.

• Clinical and Experimental Pediatrics
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• 제48권4호
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• pp.387-394
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• 2005

목 적 : 선천성 갑상선기능저하증에 대한 신생아 선별검사결과의 이상빈도는 실제 임상적으로 진단되는 질환의 발생빈도보다 훨씬 높다. 본원에서 시행되는 선천성 갑상선기능저하증에 대한 신생아 선별검사의 위양성률과 소환율을 알아보고 재태기간과 출생체중에 따른 검사결과치를 비교하여 각각의 결과에 따라 cut-off value를 재평가함으로써 임상에서 신생아 선별검사의 결과를 해석하고 질환을 진단하는데 도움을 주고자 하였다. 방 법 : 2000년 5월부터 2003년 1월까지 단국대학교병원에서 출생한 2,133명의 신생아를 대상으로 정상분만의 경우 생후 3일째, 제왕절개인 경우 생후 5일째, 신생아중환자실에 입원한 미숙아인 경우 생후 $14.3{\pm}12.4$일(5-79일) 이내에 신생아의 발뒤꿈치를 천자하여 모세혈을 검사용 채혈지에 묻혀 갑상선자극호르몬과 유리 $T_4$를 효소면역법으로 분석하였고 각각의 기존참고치인 $20{\mu}IU/mL$ 이상, 1 ng/dL 미만일 경우 소아과 외래로 불러 재검하였으며 이때 이학적 검사 및 주산기적 병력, 약물력, 모체질환 등의 여부를 조사하였고 혈청을 이용해 면역형광법에 의한 갑상선기능검사를 시행하였다. 결 과 : 1) 다른 질병이 없었던 1,749명의 갑상선자극호르몬과 유리 $T_4$의 평균${\pm}$표준편차는 각각 $9.01{\pm}5.82{\mu}IU/mL$, $1.99{\pm}0.90ng/dL$이었고 성별, 분만형태, 아프가 점수에 따른 차이는 없었다. 2) 재태연령과 출생체중에 따라 갑상선자극호르몬의 수치는 의미있는 차이가 없었고 유리 $T_4$의 수치는 의미있는 차이가 있었다(P<0.01). 3) 다른 질병이 있었던 384명의 갑상선자극호르몬과 유리 $T_4$의 평균${\pm}$표준편차는 각각 $9.17{\pm}7.22{\mu}IU/mL$, $1.52{\pm}0.75ng/dL$이었고, 건강한 신생아와 비교시 갑상선자극호르몬의 수치는 의미있는 차이가 없었고 유리 $T_4$의 수치는 의미있는 차이가 있었다(P<0.01). 4) 신생아 선별검사에서 131명이 소환되었고 재소환율은 7.48%이었으며, 이중 추적관찰이 가능했던 87명의 갑상선기능이 정상화된 기간은 출생체중과 의미있는 관계는 없었고, 출생주수와는 음의 상관관계를 보였다(P=0.042, Pearson 상관계수 -0.177). 5) 신생아 선별검사에서 재소환되어 선천성 갑상선기능저하증을 진단받은 환아는 모두 4명으로 2명은 갑상선자극호르몬 수치만 $20{\mu}IU/mL$ 이상이었고 2명은 유리 $T_4$ 수치만 1 ng/dL 미만이었으며, 3명은 건강한 신생아에, 1명은 질병이 있었던 군에 속했다. 6) Cut-off value를 본 연구에서 시행되었던 기준인 갑상선 자극호르몬이 $20{\mu}IU/mL$ 이상이거나 또는 유리 $T_4\;1\;ng/dL$ 미만인 경우 소환율, 양성예측률, 민감도, 특이도는 각각 7.48%, 2.29%, 75%, 92.6%이었다. 갑상선자극호르몬이 $20{\mu}IU/mL$ 이상이거나 유리 $T_4\;0.64\;ng/dL$ 미만인 경우에 소환율, 양성예측률, 민감도, 특이도가 각각 4.8%, 3.57%, 75%, 95.3%이었다. 결 론 : 결론적으로 선천성 갑상선기능저하증에 대한 신생아 선별검사에서 갑상선자극호르몬 및 유리 $T_4$ 모두를 선별검사로 사용하는 것은 타당하고, 현재의 cut-off value가 소환율이 높기는 하나 검사의 민감도를 고려할 때 cut-off를 바꾸기에는 문제가 있을 것으로 생각되며 향후 더 큰 대상군을 바탕으로 한 재평가가 필요하리라 생각된다.

• 한국주거학회논문집
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• 제13권2호
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• pp.65-71
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• 2002

Recently, the space organization of Korean-Chinese houses is different from that of other territories. The characteristics of eating and dinning space for Korean-Chinese Multi-family Housing are as follows ; ⅰ) The most obvious change in Korean-Chinese urban housing style was seen in kitchen space, which can be classify three types such as traditional type, improved type, and LDK type on the bases of heating and cooking method. ⅱ) Special feature of Korean-Chinese housing in Yanji city was that kitchen fulfilled important functions such as heating, cooking, dinning, sleeping, bathing and washing. Since then, each function was separated and functions of kitchen were cut down after all. iii) The arrangement of kitchen space have changeed according to the change of heating fuel, heating system, equipment, relatcd policy, etx. Multi-function kitchen discovered only in Yanji had lasted until 1980's by equipping heating floor system, which is suitable for sit-down living style. In 1990's, this kitchen style was prohibited legally, and the balcony area of kitchen widened due to the abolition of outdoor storehouse for foodstuff.

• 한국정밀공학회지
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• 제7권3호
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• pp.48-55
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• 1990

A new curve fitting algorithm based on modal analysis is introduced for extracting the modal parameters from the measured frequency responses. To compensate the effect of cut-off frequency ranges the transfer function including residual mass and residual flexibility is employed. Model parameters are computed from the newly defined form of transfer function in a simple way. The accuracy of this algorithm is proved by applying to the 3 degrees of freedom model and vibration of cantilever beam.

• International Journal of Precision Engineering and Manufacturing
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• 제1권1호
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• pp.91-97
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• 2000

Anisotropic work hardening of cold rolled low carbon steel sheets is studied. The experiments consist of two stage tensile prestraining and tensile tests. At the first prestraining, steel sheets are streteched along the rolling direction by 3% and 6% tensile strains. The second prestrains are at 0${\cric}$, 30${\cric}$, 60${\cric}$to the rolling directions by varying degrees. Tensile tests are performed on the specimens cut from the sheets after the two stage prestraining. A theoretical framework on anisotropic hardening is proposed which includes Hill's quadratic yield function, ziegler's kinematic hardening rule, and Kim and Yin's assumption on the rotation of orthotropy axes. The predicted variations of R-values with second stage tensile strain are compared with the experimental data.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.124-128
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• 1995

It is the "maturity rule" that concrete of the same mix, at the same maturity, has the same strength. In this study, the Nurse-Saul function which was proposed to account for the effects of temperature and time on strength development is used in computing maturity. After existing various functions to relate concrete strength to the maturity value are considered, new strenth-maturity function is proposed. Tests are conducted in order to compare prediction value with measured concrete strength. The constants in proposed prediction equation are determined by standard specimens(cylinders) test, and the equation is adopted to predict strength of slab. The slab was cast in the laboratory from the same batch of mole, and cores are cut from slab in order to estimate the actual strength. Tehese values are used to compare with proposed equation. equation.

• 한국정밀공학회지
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• 제26권1호
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• pp.43-50
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• 2009

Semi dry cutting known as MQL (Minimum Quantity Lubrication) machining is widely spreaded into the machining shops nowadays. The objective of this research is to suggest how to derive optimum cutting conditions for the milling process in MQL machining. To reach these goals, a bunch of finish milling experiments was carried out while varying cutting speed, feed rate, oil quantity, depth of cut and so on with MQL. Then, response surface analysis was introduced for the variance analysis and the regression model with the experimental data. Finally, desirability function based on regression model was used to obtain optimal cutting parameters and verification experiment was done.

• Journal of Ship and Ocean Technology
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• 제10권3호
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• pp.1-16
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• 2006

Despite the high cost of memory and CPU time required to resolve the boundary layer, a viscous unstructured grid solver has many advantages over a structured grid solver such as the convenience in automated grid generation and vortex capturing by solution adaption. In present study, an unstructured Cartesian grid solver is developed on the basis of the existing Euler solver, NASCART-GT. Instead of cut-cell approach, immersed boundary approach is applied with ghost cell boundary condition, which can be easily applied to a moving grid solver. The standard $k-{\varepsilon}$ model by Launder and Spalding is employed for the turbulence modeling, and a new wall function approach is devised for the unstructured Cartesian grid solver. Developed approach is validated and the efficiency of the developed boundary condition is tested in 2-D flow field around a flat plate, NACA0012 airfoil, and axisymmetric hemispheroid.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.554-559
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• 1998

Equalizing the state of charge of cell that affects the charge/discharge quality and efficiency of the battery through the charge/discharge characteristic experiments of battery source, we develope the high efficiency charge/discharge system which would be used in serial HEV with the constant engine-generator output. For this, establishes the electrical model of Ni-MH battery appropriate to the high efficiency charge/discharge conditions. There is no model of Ni-MH cell, so we used Ni-Cd model and obtain the Ni-MH model through the experiment. A reason that each cell has the same charge/discharge property for applying the cell model to serial/parallel connected battery source extensively is needed. Therefore, in this paper, propose the Ni-MH charger/discharger has the equalization charging function and selectable cut-off function.

• 한국기계가공학회지
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• 제8권3호
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• pp.98-104
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• 2009

The objective of this paper is to investigate the effect of factors on the dynamic stiffness variation of boring bar. The experiment was carried out by Taguchi Method and Orthogonal array table. The results indicate that overhang was found out to be dominant factor with 95% confident intervals and feed rate and depth of cut were insignificant. In addition, analysis of loss function shows that loss value increased sharply from 3D to 4D(D is a shank diameter). Consequently, there is critical point which changes property of dynamic stiffness.