• The Korean Journal of Nuclear Medicine Technology
• /
• v.19 no.1
• /
• pp.72-80
• /
• 2015

Purpose Serum estradiol ($E_2$) measurement is requested for diagnosing menstrual cycles, ovulation induction, infertility, and menopause. $E_2$ is measured using several methods and kits including radioimmunoassay (RIA) and chemiluminescece immunoassay (CLIA). The purpose of this study was to evaluate quality of these methods and to compare them with each other. Materials and Methods Seven radioimmunoassay kits and two CLIA methods were included in the analysis. Using standard samples and patient samples, intra-assay precision, inter-assay precision, correlation between other methods, sensitivity, and recovery rate were evaluated. Results For all tested kits and methods, coefficients of variance (CVs) of intra-assay precision test were 10.9~13.6% in low-level samples and less than 10% in medium and high-level samples. CVs of inter-assay precision test were 10.8~12.3% in low-level samples and less than 10% in medium and high-level samples with all tested kits and methods. Recovery rates were $92.7{\pm}12.4%$ for SIEMENS, $101.4{\pm}18.4%$ for DIAsource, $95.1{\pm}11.5%$ for AMP, $108.4{\pm}18.5%$ for BECKMAN COULTER, $104.2{\pm}13.5%$ for BECKMAN COULTER Ultra Sensitive, $101.3{\pm}11.6%$ for CIS Bio, and $93.1{\pm}13.2%$ for MP kits. Sensitivity was 7.5, 6.2, 5.7, 6.2, 5.3, 4.5, and 5.5 pg/mL for SIEMENS, DIAsource, AMP, BECKMAN COULTER, BECKMAN COULTER Ultra Sensitive, CIS Bio, and MP kits, respectively. The measurement by MP kit was slightly higher than those by other kits in low-level samples, and the measurement by E170 was slightly higher than those of other kits in medium and high-level samples. In the measurement of standard sample for external quality control, SIEMENS kit produced relatively lower values whereas E170, Architect, and MP kits produced relatively higher values compared with other kits. Conclusion All tested kits for $E_2$ measurement have satisfactory performance for clinical use. However, correlation between kits should be considered when test kits are to be changed, because some pairs of kits do not have correlations with each other.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.7
• /
• pp.31-40
• /
• 2004

In this paper, we analyze mathematically the performance of the gated service scheduling in the Interleaved Polling with Adaptive Cycle Time(IPACT) was proposed to control upstream traffic for Gigabit Ethernet-PONs. In the analysis, we model EPON MAC protocol as a polling system and use mean value analysis. We divide arrival rate λ into three regions and analyze each region accordingly In the first region in which λ value is very small, there are very few ONUs' data to be transmitted. In the second region in which λ has reasonably large value, ONUs have enough data for continuous transmission. In the third region, ONUs' buffers are always saturated with data since λ value is very large. We obtain average packet delay, average Queue size, average cycle time of the gated service. We compare analysis results with simulation to verify the accuracy of the mathematical analysis. Simulation requires much time and effort to evaluate the performance of EPONs. On the other hand, mathematical analysis can be widely used in the design of EPON systems because system designers can obtain various performance results rapidly. We can design appropriate EPON systems for varioustraffic property by adjusting control parameters.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.11
• /
• pp.221-228
• /
• 2014

The color and shape of the tongue reflect the physiological and clinico-pathological condition of the body. Recently, various tongue image acquisition devices have been developed for accurate diagnosis based on quantitative and objective tongue features. Since a color information is essential for tongue diagnosis, the performance of an illuminator is very important for the tongue image acquisition device. In this study, we developed an indirect illumination, which is possible to improve a homogeneity of light intensities on the tongue surface, and evaluated its performances. In order to realize the indirect illumination (II), a semi-ellipsoidal solid structure (SESS) for the light reflex was located in the system, and two high-brightness white LEDs were placed for illuminating the areas under frontal camera in the SESS. The tongue surface was illuminated by reflected light from the SESS. The light homogeneity induced by three different illuminations including the II was evaluated by calculating coefficient of variation (CV) of illuminance of five regions. The II showed less than 0.01 of CV and the direct illumination (DI) and the direct illumination with a light diffusion plate (DILDP) showed 0.16 and 0.13, respectively. The reflexed pixel ratios of tongue phantom images show 5.76%, 4.22%, 1.79% for the DI, the DILDP and the II, respectively. The homogeneity of a tongue phantom was evaluated by calculating CV of mean pixel values of six different tongue regions, and showed less than 0.06 in the II. If the II technique apply to tongue diagnosis system, it is expected to improve diagnostic accuracy in clinic.

• Korean Journal of Remote Sensing
• /
• v.39 no.6_1
• /
• pp.1413-1425
• /
• 2023

The increasing frequency of wildfires due to climate change is causing extreme loss of life and property. They cause loss of vegetation and affect ecosystem changes depending on their intensity and occurrence. Ecosystem changes, in turn, affect wildfire occurrence, causing secondary damage. Thus, accurate estimation of the areas affected by wildfires is fundamental. Satellite remote sensing is used for forest fire detection because it can rapidly acquire topographic and meteorological information about the affected area after forest fires. In addition, deep learning algorithms such as convolutional neural networks (CNN) and transformer models show high performance for more accurate monitoring of fire-burnt regions. To date, the application of deep learning models has been limited, and there is a scarcity of reports providing quantitative performance evaluations for practical field utilization. Hence, this study emphasizes a comparative analysis, exploring performance enhancements achieved through both model selection and data design. This study examined deep learning models for detecting wildfire-damaged areas using Landsat 8 satellite images in California. Also, we conducted a comprehensive comparison and analysis of the detection performance of multiple models, such as U-Net and High-Resolution Network-Object Contextual Representation (HRNet-OCR). Wildfire-related spectral indices such as normalized difference vegetation index (NDVI) and normalized burn ratio (NBR) were used as input channels for the deep learning models to reflect the degree of vegetation cover and surface moisture content. As a result, the mean intersection over union (mIoU) was 0.831 for U-Net and 0.848 for HRNet-OCR, showing high segmentation performance. The inclusion of spectral indices alongside the base wavelength bands resulted in increased metric values for all combinations, affirming that the augmentation of input data with spectral indices contributes to the refinement of pixels. This study can be applied to other satellite images to build a recovery strategy for fire-burnt areas.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.11
• /
• pp.4937-4943
• /
• 2012

Butterfly valves have been used to control the flow rate of various fluids in many industries because it have unique manageability compare to other valves. The flow rate passing through the butterfly valves can be controlled according to the coefficient of capacity calculated by disk angle change. In this study, flow analysis by 3D modeling was performed to derive the coefficient of capacity to evaluate and improve newly developed butterfly valves. Also, required measurement system was established to verify the performance of the valves, and to compare with the calculated results.

• Journal of Korean Society of Transportation
• /
• v.20 no.2
• /
• pp.71-79
• /
• 2002

This paper presents an effective alternative K-paths calculation method based on a Evolution Program (EP). We developed efficient genetic operators for path calculation. A major problem of the existing approach(similarities among the paths) can be resolved using EP's. The performance of the suggested method is evaluated and compared with the k-th shortest path for the virtual road network model by computer simulation. The results of computational experiments of the suggested method are found to be satisfactory in terms of the dispersion of alternatives.

• Journal of Advanced Navigation Technology
• /
• v.14 no.1
• /
• pp.49-56
• /
• 2010

Severe energy constraints and the low power consumption require the significance of the energy efficient error control mechanisms in wireless sensor network (WSN). In this paper, an automatic repeat request (ARQ) methodology for the analysis of error control schemes in WSN is presented such that the effects of packet length, the modulation scheme and the interference effect of the wireless channel are investigated. Moreover, an analyis of ARQ error control is provided by considering two major architectures for wireless sensor network, i.e., Mica2 and MicaZ sensor nodes. And the throughput performance of WSN with asynchronous FSK signal and DSSS-OQPSK signal with selective repeat ARQ scheme are analyzed in multiple interference environment, and the probability of receiving a correct bit and packet from target node to sink node is evaluated as a function of the channel parameter, the number of wireless sensor node, and the spreading factor.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.1
• /
• pp.56-61
• /
• 2005

Indoor air quality becomes of a concern recently in view of human health. This study investigates the air diffusion performance and the air change efficiency of a classroom, when outdoor air is introduced in addition to the heating/cooling operation of a ceiling-mounted heat pump. A CFD analysis has been performed to investigate the effect of the discharge angle of the air jets from the heat pump for both parallel and series types of outdoor air system. It is observed that the series type creates more uniform indoor environment compared to the parallel type in general. It can be concluded the discharge angle should not be larger than 40o for the parallel type, in order not to generate thermal stratification in the room.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2002.09a
• /
• pp.223-230
• /
• 2002

Earthquake resistance design has been developed many countries like Japan, USA, Mexico, New Zealand etc., which countries have experienced many earthquakes. Nowadays, earthquake resistance design has come into worldwide use. In Korea, the seismic design regulations have been established since 1988 in order to minimize the economic losses. Recently performance based design method has been adopted as a new Earthquake resistance design method. These regulations, however, are targeted for newly constructed buildings, In Korea, there are no regulations for existing buildings that built before 1988. On the other hand, in Japan and USA, the seismic performance evaluation is coded. In Japan, the evaluation index which can measure seismic performance has been made. So, we need to prepare the regulations that evaluate the seismic performance, furthermore proper retrofitting design guideline needs to be proposed when remodeling old buildings. In this research, various seismic performance evaluation methods which are being used in Japan and USA are reviewed in order to establish seismic performance evaluation index for those existing old structures in Korea.

• Membrane Journal
• /
• v.25 no.3
• /
• pp.216-222
• /
• 2015

The method measuring LEP (liquid entry pressure) was optimized to evaluate the wettabilities of hydrophobic membranes which might affect long-term durability of membrane in MD (membrane distillation) process. Conductivity of the permeate was monitored to measure the LEPs of PE (polyethylene) and PVDF (polyvinylidene di-fluoride) hollow fiber membranes from highly concentrated synthetic feed water of 20 wt% NaCl. Holding time over 5 min and the ratio of membrane area to the tank volume more than $10m^2/m^3$ were required to ensure LEP value.