• 한국보건간호학회지
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• 제26권3호
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• pp.504-517
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• 2012

Purpose: The aim of this study was to investigate gender differences in risk factors and sleep, depression, and mobility of Korean elderly with and without low back pain and sciatica. Methods: Data were derived from the 2011 Korean National Survey on Older Adults. Participants included 10,674 community-dwelling elderly. The group of elderly subjects with low back pain and sciatica and the group of elderly subjects without low back pain and sciatica were compared according to gender. Result: Age, monthly income, exercise, arthritis, osteoporosis, and providing caring support were significant risk factors for low back pain and sciatica in elderly male subjects. On the other hand, monthly income, living arrangement, arthritis, osteoporosis, providing caring support, and television watching time were significant risk factors in elderly female subjects. Significant differences in depression and mobility according to low back pain and sciatica were observed in both genders. Conclusion: Risk factors for low back pain and sciatica in elderly differed according to gender. Low back pain and sciatica showed an association with depression and mobility. These findings should be considered in planning for nursing intervention for low back pain and sciatica.

• 근관절건강학회지
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• 제14권1호
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• pp.5-12
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• 2007

Purpose: The purpose of the study was to identify the relationship between low back pain and job stress in hospital nurses. Method: A descriptive correlation research design was employed. The participants were 355 nurses who worked in a general hospital in W city Kangwon-do and consented to participate in this study. The Visual Analog Scale and job stress scale were used in this study. Analysis included descriptive statistics, t-test, ANOVA, and partial correlation coefficients. Results: Experience of low back pain for nurse in the past was 86.5% and in the present was 67.5% for low back pain which measured an average of 4.4 points for the level of low back pain. The mean score for job stress was relatively low(M=47.2). Job demand, organization system, job instability and conflict in relationships contributed to high stress scores, instead inappropriate compensation, job culture, and job autonomy contributed to low stress. There was a significant relationship between low back pain and job stress. Conclusion: These results suggest that further research is needed to develop programs to prevention and management of low back pain for nurses.

• 여성건강간호학회지
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• 제17권5호
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• pp.484-490
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• 2011

Purpose: This study was aimed to investigate the impact of job stress on low back symptoms among Clinical nurses (CNs) in university hospital. Methods: A total of 322 CNs employed in a hospital in Seoul were interviewed by a well-trained interviewer using the structured questionnaire. Data collected for this study includes demographics, social and work characteristics, low back symptoms, and job stress. To test the impact of job stress on low back symptoms, we used multiple logistic regression analysis. Results: The prevalence of low back symptoms was 25.8% in this study. Low back symptoms differed significantly by factors, such as physical work burden, past history of injury and work duration. Also low back symptoms differed significantly by organizational system among independent variables of job stress. In a multiple logistic regression analysis, the odds ratio of organizational system to low back symptoms was 2.07 after an adjustment. Conclusion: This study showed that organizational system among job stress was a significant variable in explaining low back symptoms. We suggest the improvement of organizational system category as a preventive strategy for low back pain in CNs working in hospital.

• 생물환경조절학회지
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• 제18권3호
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• pp.200-207
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• 2009

This study was conducted to analyze the variations of air temperature, relative humidity and pressure in a low pressure chamber for plant growth. The low pressure chamber was composed of an acrylic cylinder, a stainless plate, a mass flow controller, an elastomer pressure controller, a read-out-box, a vacuum pump, and sensors of air temperature, relative humidity, and pressure. The pressure leakage in the low pressure chamber was greatly affected by the material and connection method of tubes. The leakage rate in the low pressure chamber with the welding of the stainless tubes and a plate decreased by $0.21kPa{\cdot}h^{-1}$, whereas the leakage in the low pressure chamber with teflon tube and rubber O-ring was given by $1.03kPa{\cdot}h^{-1}$. Pressure in the low pressure chamber was sensitively fluctuated by the air temperature inside the chamber. An elastomer pressure controller was installed to keep the pressure in the low pressure chamber at a setting value. However, inside relative humidity at dark period increased to saturation level.. Two levels (25 and 50kPa) of pressure and two levels (500 and 1,000sccm) of mass flow rate were provided to investigate the effect of low pressure and mass flow rate on relative humidity inside the chamber. It was concluded that low setting value of pressure and high mass flow rate of mixed gas were the effective methods to control the pressure and to suppress the excessive rise of relative humidity inside the chamber.

• The Journal of Advanced Prosthodontics
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• 제6권5호
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• pp.351-360
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• 2014

PURPOSE. The aim of present study was to identify characteristic and response of mouse bone marrow (BM) derived low-adherent bone marrow mesenchymal stem cells (BMMSCs) obtained by quantification of extracellular matrix (ECM). MATERIALS AND METHODS. Non-adherent cells acquired by ECM coated dishes were termed low-adherent BMMSCs and these cells were analyzed by in vitro and in vivo methods, including colony forming unit fibroblast (CFU-f), bromodeoxyuridine (BrdU), multi-potential differentiation, flow cytometry and transplantation into nude mouse to measure the bone formation ability of these low-adherent BMMSCs. Titanium (Ti) discs with machined and anodized surfaces were prepared. Adherent and low-adherent BMMSCs were cultured on the Ti discs for testing their proliferation. RESULTS. The amount of CFU-f cells was significantly higher when non-adherent cells were cultured on ECM coated dishes, which was made by 7 days culturing of adherent BMMSCs. Low-adherent BMMSCs had proliferation and differentiation potential as adherent BMMSCs in vitro. The mean amount bone formation of adherent and low-adherent BMMSCs was also investigated in vivo. There was higher cell proliferation appearance in adherent and low-adherent BMMSCs seeded on anodized Ti discs than machined Ti discs by time. CONCLUSION. Low-adherent BMMSCs acquired by ECM from non-adherent cell populations maintained potential characteristic similar to those of the adherent BMMSCs and therefore could be used effectively as adherent BMMSCs in clinic.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.240-245
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• 2000

Fatigue crack propagation rates and characteristics of the SA516-60 steel which is used for the low temperature pressure vessels, were studied in the room temperature of $25^{\circ}C$ and low temperature ranges of $10^{\circ}C,\; -10^{\circ}C,\; -30^{\circ}C,\; -50^{\circ}C, \;and\; -70^{\circ}C4 with stress ratio of R=0.05. The obtained experimental results are as follows; 1) In the logarithmic relationship between the fatigue crack propagation rate(da/dN) and stress intensity factor K, the linear relationship was obtained up to da/dN 〉$8\times10^{-3}$/mm/cycle in the same of room temperature, but in low temperature case, the relationship was extended to the range of crack propagation rate. 2) The lower limit stress intensity factor of SA516-60 $\DeltaK_{th}$ was 15.8MPa and in the case of low temperature $-50^{\circ}C\; and\; -70^{\circ}C$, the crack propagation rate da/dN which showed a linear relation, reached rapidly to the $\DeltaK_{th}$/. As the results, the crack propagation rates of $-50^{\circ}C\; and\; -70^{\circ}C$ were lower than that of room temperature and according to the testing temperature the rates were decreased rapidly to the $\DeltaK_{th}$/. 3) On the relationship between the stress intensity factor $\DeltaK$ and the crack propagation cycle, the stress intensity factors of low cycle region was rapidly increased at low temperature, but $\DeltaK$ was increased rapidly at room temperature of high cycle. 4) On the relationship between the fatigue crack propagation rate and cycle, the fatigue crack propagation rate showed higher gradient in the room temperature than the low temperature due to the increment in ductility at low temperature.

• 한국전자파학회논문지
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• 제19권12호
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• pp.1402-1409
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• 2008

본 논문에서는 상대 유전율이 큰 low temperature co-fired ceramic 기판을 이용한 안테나의 복사 성능을 높이고, 대역폭을 개선하기 위하여 low temperature co-fired ceramic cavity backed 안테나가 제안된다. Low temperature co-fired ceramic cavity는 각 층의 접지면을 다수의 비어로 연결하여 만들어진다. 그리고, cavity의 크기가 안테나의 복사 성능과 대역폭 성능에 미치는 영향을 보여준다. 제안된 $2{\times}4$ low temperature co-fired ceramic cavity backed 안테나의 크기는 $10{\times}20\;mm^2$이며, $57{\sim}64\;GHz$ 대역에서 이득 $11.8{\sim}14.1\;dBi$, 대역폭 13 %(7.9 GHz)을 가진다. 측정 결과는 시뮬레이션 결과와 매우 잘 일치함을 보여준다.

• 가정과삶의질연구
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• 제25권6호
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• pp.33-41
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• 2007

The purpose of this study was to investigate the relationship between parents' conflict and child-rearing and school-aged children's depression in low income family and non-low income family. The subjects were 357 school-aged children who attended elementary school and who were 5th 176(49.3%) and 6th grade 181(50.7%)(boys were 206(57.7%), girls 151(42.3%)). The data were analyzed by t-test, Pearson's correlation, simple regression, enter regression(using SPSS 12.1). Major findings were as follows: (1) Parents' conflict was significantly associated with children's depression in low income and non-low income family. (2) Parents' conflict was significantly associated with parents' child-rearing in low income and non-low income family. (3) Parents' conflict partially exerted indirect effect on children's depression, controlled by parents' child-rearing in low income and non-low income family. The effect of parents' child-rearing as mediation was higher in low-income family than in non-low income family.

• 한국염색가공학회지
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• 제21권3호
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• pp.37-42
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• 2009

The low melting PET yarn has sheath/core structure: sheath portion consists of low melting point PET and core portion is regular PET. Dyeing properties of fabric made from low melting PET yarn were investigated at different dyeing temperatures. It was found that the exhaustion yield on the low melting PET fabric was higher than on regular PET fabric. The total K/S value of the dyed low melting PET fabric increased as heat setting temperature increased above $150^{\circ}C$ because the sheath portion of the low melting yarn melted. Although fastness to light of the low melting PET fabric was similar to regular PET fabric, fastness to washing was inferior to regular PET fabric by 1 grade.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.479-481
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• 2006

This paper describes a 2.5V, 320MHz low-noise and low-power Phase Locked Loop(PLL) using a noise-rejected Voltage Controlled ring Oscillator(VCO) fabricated in a TSMC 0.25um CMOS technology. In order to improve the power consumption and oscillation frequency of the PLL, The VCO consist of three-stage fully differential delay cells that can obtain the characteristic of high speed, low power and low phase noise. The VCO operates at 7MHz -670MHz. The oscillator consumes l.58mA from a 320MHz frequency and 2.5V supply. When the PLL with fully-differential ring VCO is locked 320MHz, the jitter and phase noise measured 26ps (rms), 157ps (p-p) and -97.09dB at 100kHz offset. We introduce and analysis the conditions in which ring VCO can oscillate for low-power operation.