• Journal of Preventive Medicine and Public Health
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• 제38권4호
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• pp.408-414
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• 2005

Objectives : The purpose of this study was to determine the impact of the sociodemographic and health characteristics on the out-of-pocket health spending of the individuals aged 20 and older in Korea. Methods : We used the data from the 2001 National Public Health and Nutrition Survey. The final sample size was 26,154 persons. Multiple linear regression models were used according to the age groups, that is, one model was used for those people under the age of sixty-five and the other was used for those people aged sixty-five and older. In these analyses, the expenditures were transformed to a logarithmic scale to reduce the skewness of the results. Results : Out-of-pocket health expenditures for those people under the age of 65 averaged 14,800 won per month, whereas expenditures for those people aged 65 and older averaged 27,200 won per month. In the regression analysis, the insurance type, resident area, self-reported health status, acute or chronic condition and bed-disability days were the statistically significant determinants for both age groups. Gender and age were statistically significant determinants only for the non-elderly. Conclusions : The findings from this study show that the mean out-of-pocket health expenditures varied according to the age groups and also several diverse characteristics. Thus, policymakers should consider the out-of-pocket health expenditure differential between the elderly and non-elderly persons. Improvement of the insurance coverage for the economically vulnerable subgroups that were identified in this study should be carefully considered. In addition, it is necessary to assess the impact of out-of-pocket spending on the peoples' health care utilization.

• 방송공학회논문지
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• 제20권4호
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• pp.632-640
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• 2015

본 논문에서는 오디오 이퀄라이저의 정확한 주파수 응답을 그래픽으로 빠르게 표현하는 방법을 제안한다. 주파수 축을 로그 스케일로 나타낼 경우 저대역의 정확한 주파수 응답을 표현하기 위하여 높은 해상도로 주파수 응답을 구해야 한다. 그러나 높은 해상도의 주파수 응답을 구하기 위해 많은 계산량이 필요하고, 이에 따라 주파수 응답의 그래픽 표현을 실시간으로 제공하기 어렵다. 이와 같은 계산량 문제를 해결하기 위하여 본 논문에서는 낮은 해상도로 중대역에서 구한 가상 주파수 응답을 이용하는 방법을 제안한다. 이퀄라이저를 구성하는 각 필터에 대하여 중대역에서 가상 주파수 응답을 구한 후 원하는 주파수 위치로 이동하여 해당 필터의 주파수 응답을 구하고, 모든 필터의 주파수 응답을 결합하여 이퀄라이저의 최종 주파수 응답을 구한다. 실험을 통하여 제안한 방법으로 구한 주파수 응답이 많은 계산량을 사용하여 높은 해상도로 구한 주파수 응답과 동등한 모양을 가지는 것을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.174-174
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• 2008

Non-volatile memories using ferroelectric-gate field-effect transistors (Fe-FETs) with a metal/ferroelectric/semiconductor gate stack (MFS-FETs) make non-destructive read operation possible. In addition, they also have features such as high switching speed, non-volatility, radiation tolerance, and high density. However, the interface reaction between ferroelectric materials and Si substrates, i.e. generation of mobile ions and short retention, make it difficult to obtain a good ferroelectric/Si interface in an MFS-FET's gate. To overcome these difficulties, Fe-FETs with a metal/ferroelectric/insulator/semiconductor gate stack (MFIS-FETs) have been proposed, where insulator as a buffer layer is inserted between ferroelectric materials and Si substrates. We prepared $SrBi_2Ta_2O_9$ (SBT) film as a ferroelectric layer and $LaZrO_x$ (LZO) film as a buffer layer on p-type (100) silicon wafer for making the MFIS-FET devices. For definition of source and drain region, phosphosilicate glass (PSG) thin film was used as a doping source of phosphorus (P). Ultimately, the n-channel ferroelectric-gate FET using the SBT/LZO/Si Structure is fabricated. To examine the ferroelectric effect of the fabricated Fe-FETs, drain current ($I_d$) versus gate voltage ($V_g$) characteristics in logarithmic scale was measured. Also, drain current ($I_d$) versus drain voltage ($V_d$) characteristics of the fabricated SBT/LZO/Si MFIS-FETs was measured according to the gate voltage variation.

• Journal of Advanced Marine Engineering and Technology
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• 제40권10호
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• pp.899-905
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• 2016

Wireless access in vehicle environment (WAVE) communication is currently being researched as core wireless communication technologies for cooperative intelligent transport systems (C-ITS). WAVE consists of both vehicle to vehicle (V2V) communication, which refers to communication between vehicles, and vehicle to infrastructure (V2I) communication, which refers to the communication between vehicles and road-side stations. V2I has a longer communication range than V2V, and its communication range and reception rate are heavily influenced by various factors such as structures on the road, the density of vehicles, and topography. Therefore, domestic environments in which there are many non-lines of sight (NLOS), such as mountains and urban areas, require optimized communication channel modeling based on research of V2I propagation characteristics. In the present study, the received signal strength indicator (RSSI) was measured on both an experience road and a test road, and the large-scale characteristics of the WAVE communication were analyzed using the data collected to assess the propagation environment of the WAVE-based V2I that is actually implemented on highways. Based on the results of this analysis, this paper proposes a WAVE communication channel model for domestic public roads by deriving the parameters of a dual-slope logarithmic distance implementing a two-ray ground-reflection model.

• 대한전자공학회논문지
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• 제14권3호
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• pp.25-31
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• 1977

Fe O 와 V O 를 적당한 mole비로 혼합하여 H -CO 분위기 중 1,100℃에서 10시간씩 5∼6회 반복소성하여 Fe V O Spinel을 제조하였다. 제조된 시편의 온도에 대한 저항률을 측정하고 이로부터 활성화에너지를 구해서 시편의 도전기구를 고찰하고, x, 주위온도, 시편의 두께 및 인가전압 상승률에 대한 I-V 특성곡선을 얻어서 부성저항 발생기구의 해명을 시도하였다. Fe V -O spinel의 도전은 주로 B자리의 Fe 와 F 사이의 전자 hopping에 기인되며, 부성저항은 filament형의 통전로에 기인되는 열적현상이라 생각된다.

• 대한안전경영과학회지
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• 제13권1호
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• pp.107-114
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• 2011

Location-Based Service(LBS) is a service that provides a variety of convenience in life using location information that can be obtained by mobile communication network or satellite signal. In order to provide LBS precisely and efficiently, we need the location determination technology, platform technology and server technology. In this study, we studied on how we can reduce the error on location determination of objects such people and things. Fingerprint location determination method was applied to this study because it can be used at current wireless communication infrastructure and less influenced by a variety of noisy environment than other location determination methods. We converted the probability value to logarithmic scale value because using the sum of k probability values is not suitable to be applied to weight determination. In order to confirm the performance of suggested method, we developed location determination test program with Visual Basic 6.0 and performed the test. According to indoor and outdoor test results, the suggested stochastic method reduced the distance error by 17%, 18% and 9% respectively at indoor environment and 25%, 11% and 4% at outdoor environment compared with deterministic NN, kNN and kWNN fingerprint methods.

• KSBB Journal
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• 제22권6호
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• pp.443-446
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• 2007

관상심장질환 바이오마커의 하나인 CRP를 batch형 수정진동자 면역센서에 의하여 다음과 같이 분석하였다. 센서시스템의 작동은 직접결합방식에 의하여 행하였으며 CRP에 대한 항체의 최적 고정화농도는 $50{\mu}g/ml$이었다. 시스템의 반응완충용액으로 0.1 M 인산완충용액 (pH 7.0)을 사용하였고 시스템 작동은 baseline 안정화, 시료첨가 및 측정, 10 mM NaOH에 의한 센서 칩 재생의 순으로 행하였다. 이중로그척도로 표시하였을 때 0.27-106.00 nM 범위의 쥐 유래 CRP에 대하여 센서반응과 직선상의 관계를 이루었으며 센서의 검출한계는 0.53 nM이었고 재사용성도 양호하였다.

• Applied Biological Chemistry
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• 제49권3호
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• pp.254-258
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• 2006

내분비계장애물질에 노출된 어류의 에스트로겐 활성에 대한 생물지표단백질인 vitellogenin을 검출하는 압전류적 면역센서를 잉어 vitellogenin에 대한 항체와 AT-cut 수정진동자를 생물요소와 변환기로 사용하여 구성하고 이를 이용한 잉어 vitellogenin 검출을 행하였다. 이형이기능성의 티올화 가교화제인 sulfosuccinimidyl 6-[3-(2-pyridyldithio)propionamido]hexanoate 처리에 의하여 티올화된 항체를 수정진동자상의 금전극에 화학흡착법에 의하여 고정화하여 센서 chip을 제조하였다. 센서반응을 위한 반응완충용액을 0.1M sodium phosphate(pH 7.4)로 선정한 후 $0.4864{\sim}486.4000\;nM$의 vitellogenin 용액을 가하였을 때 농도의존적인 센서반응의 증가가 나타났으며 이 때 잉어 vitellogenin에 대한 검출한계는 0.4864 nM로 추정되었다.

• Wind and Structures
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• 제24권6호
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• pp.579-611
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• 2017

Bora is a strong, usually dry temporally and spatially transient wind that is common at the eastern Adriatic Coast and many other dynamically similar regions around the world. One of the Bora main characteristics is its gustiness, when wind velocities can reach up to five times the mean velocity. Bora often creates significant problems to traffic, structures and human life in general. In this study, Bora velocity and near-ground turbulence are studied using the results of three-level high-frequency Bora field measurements carried out on a meteorological tower near the city of Split, Croatia. These measurements are analyzed for a period from April 2010 until June 2011. This rather long period allows for making quite robust and reliable conclusions. The focus is on mean Bora velocity, turbulence intensity, Reynolds shear stress and turbulence length scale profiles, as well as on Bora velocity power spectra and thermal stratification. The results are compared with commonly used empirical laws and recommendations provided in the ESDU 85020 wind engineering standard to question its applicability to Bora. The obtained results report some interesting findings. In particular, the empirical power- and logarithmic laws proved to fit mean Bora velocity profiles well. With decreasing Bora velocity there is an increase in the power-law exponent and aerodynamic surface roughness length, and simultaneously a decrease in friction velocity. This indicates an urban-like velocity profile for smaller wind velocities and a rural-like velocity profile for larger wind velocities. Bora proved to be near-neutral thermally stratified. Turbulence intensity and lateral component of turbulence length scales agree well with ESDU 85020 for this particular terrain type. Longitudinal and vertical turbulence length scales, Reynolds shear stress and velocity power spectra differ considerably from ESDU 85020. This may have significant implications on calculations of Bora wind loads on structures.

• 대한조선학회논문집
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• 제47권5호
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• pp.647-655
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• 2010

In this paper, a numerical study is carried out for super-pipe, flat plate and axisymmetric body flows to investigate a validity of using wall function and high $y_1^+$ in calculation of high Reynolds number flow. The velocity profiles in boundary layer agree well with the law of the wall. And it is found that the range of $y^+$��which validated the logarithmic law of the wall grows with increasing Reynolds number. From the result, an equation is suggested that can be used to estimate a maximum $y^+$ value of validity of the log law. And the slope(1/$\kappa$) of the log region of the numerical result is larger than that of experimental data. On the other hand, as $y_1^+$ is increasing, both the friction and the pressure resistances tend to increase finely. When using $y_1^+$ value beyond the range of log law, the surface shear stress shows a significant error and the pressure resistance increases rapidly. However, when using $y_1^+$ value in the range, the computational result is reasonable. From this study, the use of the wall function with high value of $y_1^+$ can be justified for a full scale Reynolds number ship flow.