• 품질경영학회지
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• 제21권1호
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• pp.171-180
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• 1993

Variables, x and y are said to have a linear relation if $y={\beta}_0+{\beta}_1\;x$, and ${\beta}_0$ and ${\beta}_1$ are constants. The relationship is called a structural relationship if x has positive variance (i.e., x is not fixed) and only error-prone measurements of x and y can be obtained. This paper derives (to order $n^{+1/2}$) an approximate distribution of the Studentized test statistic for testing hypotheses about the slope parameter, ${\beta}_1$ in a simple linear structural model. A simulation study suggests our approximate distribution is more accurate approximation to the exact distributions of the Studentized statistic than is the limiting distribution.

• KSBB Journal
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• 제13권6호
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• pp.724-729
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• 1998

To develop a large scale countercurrent single pass heat exchanger for continuous transportation and sterilization of soybean paste, microflora and color value of sterilized soybean paste were examined at various sterile condition. Aerobes, anaerobes, molds, yeasts and lactic acid bacteria were 5.1 x 107 CFU/g, 7.1 x 107 CFU/g, 2.6 x 105 CFU/g, 4.3 x 106 CFU/g, 1.3 x 107 CFU/g, respectively in raw soybean paste. In gold band ampoule test, aerobes and anaerobes of soybean paste were viable up to 90$^{\circ}C$, but become unviable at 100$^{\circ}C$. Molds decreased rapidly and yeasts decreased slowly from 70$^{\circ}C$. Lactic acid bacteria were unviable at 60$^{\circ}C$ within 10 min. In color test, Hunter L, a, and b values of soybean paste were 50.2, +5.6, and +17.8, respectively. After heating in polyethylene film bag at 80$^{\circ}C$, Hunter values were not so much changed and become 50.2, +4.7, and +19.7, respectively. The micorflora and color of soybean paste sterilized in a large scale heat exchanger system resulted in very similar to those of gold band ampoule and polyethylene film bag by effective heat transfer.

• 한국항공우주학회지
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• 제35권4호
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• pp.347-352
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• 2007

논문에서는 과학기술위성 2호용으로 개발된 탑재체데이터 수신시스템(Data Receiving Equipment, DRE)을 소개하고 개발된 준비행모델(Proto Flight Model, PFM)에서의 기능 및 성능 시험 결과를 제시 한다. 탑재체데이터 수신시스템은 X 대역 수신기, 데이터 합성장치(Data Combine Equipment, DCE)와 수신 저장 컴퓨터(Receiving and Archiving Computer, RAC)로 구성되어 있다. DCE는 I&Q 신호 합성기와 ECL 신호 분배기로 구성 된다. RAC은 데이터 수신 카드(Data Receiving Card, DRC)와 소프트웨어인 ST2RAS(STSAT-2 Receiving and Archiving Software, ST2RAS)로 구성된다. X 대역 수신기를 통해서 수신된 I, Q 데이터는 DCE를 통해서 I&Q 데이터로 합성된다. 합성된 데이터는 데이터 수신 카드를 통해서 수신 저장 컴퓨터의 RAID(Redundant Array of Inexpensive Disk)에 저장되고, 이 데이터는 ST2RAS의 전처리를 통해서 위성의 상태 정보와 탑재체 정보로 분리된다. 탑재체데이터 수신시스템에 대한 기능 시험과 열진공 시험을 통해서 10-6 의 BER(Bit Error Rate) 요구사항을 만족하는 결과를 확인하였다.

• 한국환경보건학회지
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• 제19권2호
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• pp.46-54
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• 1993

This study was carried out on the stabilized/solidified treatment for the reducing leachability of hazardous heavy metals copper, lead, chromium and cadmium in the hazardous sludge which treated to be unleached heavy metals by sodium diethyl dithiocarbamate. Cement matrix was analyzed for the leachability of 24 hrs and dynamic leaching test, structure and the optimum condition for the stabilization and solidification of the hazardous sludge. In 28 days of curing time the unconfined compressive strength was 21.5 kg/cm$^2$ at the ratio of portland cement (0.5)+fly ash (0.25) and 23.5 kg/cmz at the ratio of portland cement (0.5)+fly ash (0.25) + cake (0.25). High concentration of Pb, Cr and Cd in the sea water and Cu in the distilled water were leached at the dynamic leaching test. The concentration of leaching heavy metals for specimens which were tested 24 hrs were found low leachability with decreasing pH of leachant. According to dynamic leaching test, the low level of copper, lead, cadmium and chromium were leached in the cement matrix with sodium diethyl dithiocarbamate. But the effective diffusion coefficient of unleached cement matrix which was treated sodium diethyl dithiocarbamate was decreased above 2 times than that of cement matrix. The relation of leachant renewal period (Y) and cumulative fraction ion leached (X) was the following regression equations. Solidification with unleached agent. Y$_{Cu}$ = 1413752X + 247, Y$_{Pb}$ = 223501IX + 214, Y$_{Cr}$ = 8310601X - 472, Y$_{Cd}$ = 168787X + 1061 The structure of' solidified matrix with X-ray diffraction analysis was composed more Ca(OH)$_2$, Si, Mg(OH)$_2$ and Al in the unleached cement matrix than those in cement matrix.

• 지역사회간호학회지
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• 제25권3호
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• pp.198-206
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• 2014

Purpose: The purposes of this study were to identify the prevalence and influencing factors of fecal incontinence, and to analyze the association between fecal incontinence and depression. Methods: The subjects of this study were 233 women living in rural areas, and data were collected using questionnaires from February 24 to May 30, 2012. Fecal incontinence was measured with the Continence Grading Score, and depression with the Geriatric Depression Scale. Collected data were analyzed using SPSS through $x^2$-test, Fisher's exact test, t-test and ANOVA. Results: Of the subjects, 16.7% had fecal incontinence. The prevalence of fecal incontinence was higher in older women ($x^2=23.55$, p<.001), those with vaginal delivery ($x^2=4.81$, p=.049), those with parity of 4 or more ($x^2=13.47$, p=.003), and those with urinary incontinence ($x^2=26.36$, p<.001). The level of depression was significantly higher in older women (F=19.27, p<.001), those with low academic qualification (F=18.17, p<.001), those with urinary incontinence (F=4.15, p=.043), and those with fecal incontinence (F=14.90, p<.001). Conclusion: These results suggest that there should be supports by public health care for fecal incontinence prevention and care programs in order to promote the physical and emotional health of rural women.

• 한국보건간호학회지
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• 제31권2호
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• pp.272-283
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• 2017

Purpose: This descriptive study compared changes in life style and health perceptions before and after the onset of coronary heart disease in 100 patients. Methods: Data were from May to July in 2016 through questionnaires and medical records. The collected data were analyzed by a $x^2$ test, and paired t-test using SPSS 12.0. Results: After the onset of heart disease, significant decreases were observed in smoking ($x^2=17.21$, p<.001) and drinking ($x^2=43.56$, p<.001), while exercise increased significantly ($x^2=32.77$, p<.001). Appetite, stress and health state were significantly decreased after the onset of heart disease (t=3.18, p=.002, t=3.55, p=.001, t=4.43, p<.001), and knowledge about disease was significantly increased after the onset of heart disease (t=-13.66, p<.001). Conclusion: The results of this study indicate that continuous follow-up management programs including smoking and drinking cessation, exercise, appetite and stress management should be developed and implemented for Coronary Heart Disease with PCI.

• Ocean and Polar Research
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• 제27권4호
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• pp.443-450
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• 2005

The ratio of breeding pairs of brown skuas (Catharacta lonnbergi), south polar skuas (C. maccormicki) and mixed species pairs between Barton and Weaver peninsulas remained the same $(X^2-test,\;X^2=0,503,\;df=2,\;p=0.778)$. The nests of skuas were clustered on Barton, whereas they were distributed randomly on the Weaver peninsula. The distance between brown skua nests, and that of mixed species pair nests were longer than those of south polar skua nests. Brown skua nests were distributed along the coast. Whereas, the nests of mixed species pairs and south polar skuas were found more frequently inland (Kruskal-Wallis, $X^2=11.631$, df=2, p<0.005). There was no interspecific difference in the distances between skua nests and Penguin rookery at Barton (Kruskal-Wallis, $X^2=2.153$, df=2, p=0.341) or at King Sejong Station (ANOVA, F=1.483, df=2, p=0.229). In general, skuas prefer lower locales (<125m above sea level) for their nest building sites. Brown skua nests were distributed mainly on the beach, whereas south polar skua were distributed on the predominant periglacial landforms and till areas $(X^2-test,\;X^2=24.988,\;df=8,\;p<0.005)$.

• 한국항공우주학회지
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• 제43권3호
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• pp.243-256
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• 2015

극초음속 비행체 개발 연구의 일환으로 소형 발사체나 과학로켓을 이용한 여러 비행 시험 프로그램이 진행되었다. 국제 협력으로 진행된 호주의 HyShot 프로그램은 과학로켓을 이용한 대표적인 스크램제트 엔진 비행시험 프로그램이며, 이후 다양한 탑재체에 대한 유사한 극초음속 비행 시험 프로그램들이 진행되었다. 미국에서는 DARPA와 AFRL 및 ONR이 각각 Falcon HTV-2, X-51A 및 HyFly의 프로그램을 수행하였으며, 호주와 국제협력으로 HyCAUSE, HIFiRE 비행시험 프로그램을 수행하였다. 그 밖에도 프랑스는 X-51A과 유사한 LEA 프로그램을 진행하고 있으며, 러시아 및 중국, 인도는 극초음속 방위 체계 개발을 목표로 비행시험을 진행하고 있는 것으로 보인다. 본 논문에서는 향후 국내에서 유사 프로그램을 수행할 시 참고할 수 있도록, 이들 프로그램의 목표 및 기술 요소와 경과 및 프로그램 사이의 관계 등을 정리하였다.

• 마이크로전자및패키징학회지
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• 제24권1호
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• pp.45-50
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• 2017

본 연구에서는 Sn-0.7Cu-xZn 무연솔더와 OSP 표면처리 된 솔더접합부의 전단강도를 Zn 함유량에 따라 평가하였다. 다섯 종류의 Sn-0.7Cu-xZn (x=0, 0.5, 1.0, 1.5, 2.0 wt.%) 솔더페이스트를 제작한 뒤, OSP(organic solderability preservative) 표면처리 한 PCB(printed circuit board) 기판의 전극에 리플로우 공정으로 180 um 직경의 솔더볼을 형성하였다. 전단강도는 두 가지 조건의 전단속도(0.01, 0.1 m/s)로 고속전단시험(high speed shear test)을 통해 측정하였고, 고속전단시험 시에 측정된 F-x(Force-distance) curve를 통해 파괴에너지(fracture energy)를 계산하였다, SEM(주사전자현미경, scanning electron microscopy)과 EDS(energy dispersive spectroscopy) 분석을 통하여 단면과 파단면을 관찰하였고, 금속간 화합물(intermetallic compound, IMC) 층을 분석하였다. Zn 함유량이 증가함에 따라 금속간 화합물 층의 두께는 감소하였고, Zn 함유량이 0.5 wt.%일 때 가장 높은 전단 강도(shear strength)를 나타내었다. 전체적으로 높은 전단속도 조건의 전단강도 값이 낮은 전단속도 조건의 전단강도보다 높았다.

• 한국환경보건학회지
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• 제36권4호
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• pp.313-322
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• 2010

The aim of this research was to apply experimental design methodology to optimization of conditions of electrochemical oxidation of Rhodamine B (RhB) and N, N-Dimethyl-4-nitrosoaniline (RNO, indicative of the OH radical). The reactions of electrochemical oxidation of RhB degradation were mathematically described as a function of the parameters of current ($X_1$), NaCl dosage ($X_2$) and pH ($X_3$) and modeled by the use of the central composite design. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the removal efficiency of RhB and RNO and test variables in a coded unit: RhB removal efficiency (%) = $94.21+7.02X_1+10.94X_2-16.06X_3+3.70X_1X_3+9.05X_2X_3-{3.46X_1}^2-{4.67X_2}^2-{7.09X_3}^2$; RNO removal efficiency (%) = $54.78+13.33X_1+14.93X_2- 16.90X_3$. The model predictions agreed well with the experimentally observed result. Graphical response surface and contour plots were used to locate the optimum point. The estimated ridge of maximum response and optimal conditions for the RhB degradation using canonical analysis was 100.0%(current, 0.80 A; NaCl dosage, 2.97% and pH 6.37).