• Journal of the Ergonomics Society of Korea
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• v.31 no.5
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• pp.647-655
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• 2012

Objective: The purpose of this study was to confirm difference between angular foot movement time and existing foot Fitts' law predicting times, and to develop the angular foot Fitts' law in the foot tapping task. Background: Existing studies of foot Fitts' law focused on horizontal movement to predict the movement time. However, when driving a car, humans move their foot from the accelerator to the brake with a fixed heel. Therefore, we examined the experiment to measure angular foot movement time in reciprocal foot tapping task and compared to conventional foot Fitts' law predicting time. And, we developed the angular foot Fitts' law. Method: In this study, we compared the angular foot movement time in foot tapping task and the predicted time of four conventional linear foot Fitts' law models - Drury's foot Fitts' law, Drury's ballistic, Hoffmann's ballistic, Hoffmann's visually-controlled. 11 subjects participated in this experiment to get a movement time and three target degrees of 20, 40, and 60 were used. And, conventional models were calculated for the prediction time. To analyze the movement time, linear and arc distance between targets were used for variables of model. Finally, the angular foot Fitts' law was developed from experimental data. Results: The average movement times for each experiment were 412.2ms, 474.9ms, and 526.6ms for the 89mm, 172mm, and 253mm linear distance conditions. The results also showed significant differences in performance time between different angle level. However, all of conventional linear foot Fitts' laws ranged 135.6ms to 401.2ms. On the other hand, the angular foot Fitts' law predicted the angular movement time well. Conclusion: Conventional linear foot Fitts' laws were underestimated and have a limitation to predict the foot movement time in the real task related angular foot movement. Application: This study is useful when considering the human behavior of angular foot movement such as driving or foot input device.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.87-94
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• 2020

Social reviews such as SNS feeds and blog articles have been widely used to extract keywords reflecting opinions and complaints from users' perspective, and often include proper nouns or new words reflecting recent trends. In general, these words are not included in a dictionary, so conventional morphological analyzers may not detect and extract those words from the reviews properly. In addition, due to their high processing time, it is inadequate to provide analysis results in a timely manner. This paper presents a method for efficient keyword extraction from social reviews based on the notion of cohesion scoring. Cohesion scores can be calculated based on word frequencies, so keyword extraction can be performed without a dictionary when using it. On the other hand, their accuracy can be degraded when input data with poor spacing is given. Regarding this, an algorithm is presented which improves the existing cohesion scoring mechanism using the structure of a word tree. Our experiment results show that it took only 0.008 seconds to extract keywords from 1,000 reviews in the proposed method while resulting in 15.5% error ratio which is better than the existing morphological analyzers.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.1
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• pp.15-18
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• 2003

High purity single crystalline calcium fluoride ($CaF_2$) has excellent optical transmission characteristics down to deep UV and is therefore selected as the main optical material for the next generation of lithography apparatus operating at wavelength of 157 nm. The growth of large sized $CaF_2$ single crystals with the required properties for this optical application can be achieved only by optimizing the crystal growth process by the aid of numerical simulation. This needs especially a precise calculation of the heat transport and temperature distribution in the solid and liquid $CaF_2$ under crystal growth conditions. As $CaF_2$ is considered to be semitransparent, the internal radiative heat transfer in $CaF_2$ plays an decisive role in the simulation of the heat transport. On the other hand it is very difficult to obtain quantitative experimental data for evaluating numerical models as $CaF_2$ is extremely corrosive at high temperatures. In this work we present a newly developed experimental technique to perform temperature measurements in $CaF_2$-crystal as well as in the melt under conditions of crystal growth process. These experimental results are compared to calculated temperature data, which were obtained by using different numerical models concerning the internal heat transfer in semitransparent $CaF_2$. It will be shown, that an advanced model, which was developed by the authors, gives a much better agreement with experimental data as a standard model, which was taken from the literature.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1551-1555
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• 2006

This study was carried out to investigate the use of three different mathematical models (Wood, Quadratic and Cubic) for describing the lactation curve of Akkaraman ewes. Data were collected from 42 ewes that were three years of age and from the same flock raised in The State Farm of $G{\ddot{o}}zl{\ddot{u}}$ in Konya Province. All ewes lambed in March. They were hand milked twice daily and the first milk test was performed with in the first month after lambing (mean = 27.8 day, SD = 4.26) in an attempt to describe the peak yield. The differences between estimated total milk yields by the models were not significant. The models were adequate for describing total milk yield. The differences between peak yields were not significant. The Wood model estimated the time of peak yield earlier than the other models and observed values (p<0.01). Especially the Cubic model's peak time was very close to really peak time (34.30 vs. 35.33 days). $R^2$ values of the models ranged from 85.85% to 96.20%. The Cubic model gave the best $R^2$ value (p<0.01). Correlation coefficients between descriptive values of the models changed from 0.32 to 1.00. Total milk yields of the models were highly correlated (above 0.99) with the total milk yield calculated by the Fleischmann method (p<0.01). As a result the Cubic model showed the best fit to the data collected from Akkaraman ewes and allowed a suitable description of the shape of the lactation curve.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.1
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• pp.17-24
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• 2018

Military camera equipment has a problem that observability is inferior due to various shaking factors. In this paper, we propose an image stabilization algorithm considering performance and execution time to solve this problem and implemented it in Zynq SoC. We stabilized both the simple shaking in the fixed observation position and the sudden shaking in the moving observation position. The feature of the input image is extracted by the Sobel edge algorithm, the subblock with the large edge data is selected, and the motion vector, which is the compensation reference, is calculated through template matching using the 3-step search algorithm of the region of interest. In addition, the proposed algorithm can distinguish the shaking caused by the simple shaking and the movement by using the Kalman filter, and the stabilized image can be obtained by minimizing the loss of image information. To demonstrate the effectiveness of the proposed algorithm, experiments on various images were performed. In comparison, PSNR is improved in the range of 2.6725~3.1629 (dB) and image loss is reduced from 41% to 15%. On the other hand, we implemented the hardware-software integrated design using HLS of Xilinx SDSoC tool and confirmed that it operates at 32 fps on the Zynq board, and realized SoC that operates with real-time processing.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.15-21
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• 2016

According to the disaster statistics issued by the Ministry of Public Safety and Security, traffic accidents, fire, collapses and others are classified into twenty-three (23) categories. In the past, disasters were mainly caused by the influence of nature, such as typhoon or drought. On the other hand, as society has become city-centered, social disasters' types, frequencies and scales are becoming more diversified and ever-increasing. However, there are no specific criteria and assessment methods that can measure degrees of social disasters-related risks objectively. Therefore, this study targeted traffic accidents, fire and collapses from major social disasters, utilized data that are related to occurrence rate, scale of casualties and scale of property loss in past eight years, and calculated the disaster risk index using the distance (Euclidean distance) between two points on the 3D spatial coordinates, in order to make the objective assessment by social disaster type possible. These results will enable the objective evaluation of risk index of major social disaster to be used as the foundational data when building the national disaster management system.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.226-226
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• 2016

PHOLED devices which have the structure of ITO/HAT-CN(5nm)/NPB(50nm)/EML(30nm)/TPBi(10nm)/Alq3(20nm)/LiF(0.8nm)/Al(100nm) are fabricated to investigate the green emission profile in EML by using a gasket doping method. CBP and Ir(ppy)3 (2% wt) are co-deposited homogeneously as a background material of EML for green PHOLED, then a 5nm thickness of additionally doped layer by Ir(btp)2 (8% wt) is formed as a profiler of the green emission. The total thickness of the EML is maintained at 30nm while the distance of the profiler from the HTL/EML interface side (x) is changed in 5nm steps from 0nm to 25nm. As shown in Fig. 1, the green (513nm) peak from Ir(ppy)3 is not observed when Ir(btp)2 is also doped homogeneously because Ir(ppy)3 works as an gasket dopant of the Ir(btp)2 :CBP system. Therefore, in this experment, Ir(btp)2 can be used as a profiler of the green emission in CBP:Ir(ppy)3 system. The emission spectra from the PHOLED devices with different x are shown in Fig. 2. In this gasket doping system, stronger red peak means more energy transfer from green to red dopant or higher exciton density by green dopant. To find the green emission profile, the external quantum efficiency (EQE) at 3mA/cm2 for red peaks are calculated. More green light emission at near EML/HBL interface than that of HTL/EML is observed (insert of Fig. 2). This means that the higher exciton density at near EML/HBL interface in homogeneously doped CBP with Ir(ppy)3. As shown in Fig. 3, excitons can be quenched easily to HTL(NPB) because the T1 level of HTL(2.5eV) is relatively lower than that of EML(2.6eV). On the other hand, the T1 level of HBL(2.7eV) is higher than that of EML.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.4
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• pp.75-83
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• 2016

Streamflow is composed of baseflow and direct runoff. However, most of streamflow during dry seasons depends on baseflow. Thus, baseflow analysis is very important to simulate streamflow of dry seasons. Generally, baseflow analysis is conducted using watershed-scale runoff models due to diffilculty of measuring baseflow. However, it is needed to understand and review how the model simulates baseflow because each model uses inherent baseflow analysis techniques. In this study, SWAT, HSPF, PRMS-IV were reviewed focusing on baseflow and soil water. HSPF and PRMS-IV calculate baseflow using the variables which depends on user, so the baseflow analysis results of HSPF and PRMS-IV are not consistent. Moreover, soil structures which were assumed from HSPF and PRMS-IV, since these two models assume soil structure as two soil zones and three conceptual reservoirs, were not enough to describe real soil structure. On the other hand, baseflow in SWAT is calculated using baseflow recession constant which can consider the characteristics of aquifer and also, soil structure in SWAT is similar to real soil structures. Thus, baseflow analysis result from SWAT was concluded as the most suitable and reliable model because SWAT can reflect the characteristics and soil structure which is close to reality.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.10
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• pp.4747-4753
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• 2016

Background: The prevalence of Helicobacter pylori (H. pylori) infection in Indonesia has been reported to be exceedingly low. The purpose of our study was to confirm whether this is the case in Northern Jakarta using a sensitive 13C-urea breath test (UBT), and to examine any associations with lifestyle/environment factors and potential routes of transmission. Methods: We recruited a total of 196 subjects from a low-income community in Northern Jakarta, Indonesia, data from 193 who completed a questionnaire about their lifestyle/environment and had UBT being included as the final. Odds ratios (ORs) adjusted for sex and age with 95% confidence intervals (CIs) were calculated using a logistic regression model. Results: The overall H. pylori infection rate was 15.0% (95%CI, 10.3-20.9), with variation among Javanese (9.1%, total=77), Buginese (40.0%, 35), Betawi (9.1%, 33), Sundanese (3.7%, 27), and Batak (40.0%, 5). On multivariate analysis, the ORs for intake of soybean milk, cucumber more than once a week, infrequent hand washing practice before meals, and alcohol consumption were 0.10 (95%CI: 0.01-0.97), 6.61 (95%CI: 1.87-23.3), 4.10 (95%CI: 1.15-14.6), and 61.9 (95%CI: 1.67-2300.8), respectively. Rates for Buginese (OR=7.84; 95%CI: 1.82-33.8) and Batak (OR=20.1; 95%CI: 1.90-213.2) were significantly higher than for Javanese. Conclusions: The H. pylori infection rate in this study was relatively low, in line with previous studies. Regarding ethnicity factors, Buginese and Batak reported eating food using fingers more frequently than Javanese, Betawi, and Sundanese. Our study indicated that person-person transmission is possible in this low prevalence area. The low infection rates for H. pylori among Javanese, Betawi, and Sundanese ethnics could be partly due to their sanitary practices.

• Korean Journal of Community Nutrition
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• v.4 no.2
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• pp.139-148
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• 1999

This study was designed to assess the iron nutritional status of girls at puberty in Kangnung area. The subjects consisted of 161 adolescents in sixth-grade in primary school and first-grade in middle school girls. Anthropometric measurements were taken for body weight, height, percentage of body fat, and circumferences of waist and hip. Nutrient intakes were assessed by modified 24-hour recall method. Food models and other measuring tools were also used. Fasting blood samples were obtained and analyzed for hemoglobin(Hb) concentration, hematocrit(Hct), serum iron(FE) and total iron binding capacity(TIBC). Mean values for Hb, Hct, Fe, TIBC, TS and serum ferritin were $13.6{\pm}0.9g/dl$, $39.6{\pm}3.9%, 91.3{\pm}36.3{\mu}g/dl$, $327.9{\pm}45.2{\mu}g/dl$, $28.3{\pm}11.8%$ and $37.4{\pm}24.2ng/ml$, respectively. Prevalence of iron deficiency greatly varied by indices from 4.8% when judged by Hb to 18.4% by serum Fe concentration. The Hb concentration was positively correlated with Hct(r=0.641), serum iron(r=0.266) and transferrin saturation(r=0.237)(p<0.05). On the other hand, serum ferritin concentration showed significantly negative correlation with TIBC(r=-0.572). Mean daily intake of iron was 14.94mg and heme iron intake was 1.13mg and which was 7.6% of total iron intake. Total absorbable iron calculated by the method of Mosen was 1.38mg and bioavailability of dietary iron was 9.3%. These results suggest that the prevalence of iron deficiency of pubertal girls is very high, therefore the guidelines for diet and social supports, such as, school food service system should be provided to improve their iron status in middle school students.