• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.70-74
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• 2018

In typical spectroscopic ellipsometry, the optical and geometrical properties of thin film and nano pattern can be obtained by measuring the polarization state of light reflected/transmitted from the object by rotating a analyzer or a compensator. We proposed a snapshot spectroscopic ellipsometric system based on a modified Michelson interferometer to overcome the time-consuring measurement principle due to rotating part. The proposed system provides spectral ellipsometric parameters (psi, delta) in real time by using a single spectral interference signal generated in the interferometric polarization module. However, it has a long-term stability problem resulting in delta(k) drift. In this paper, it is experimentally proved that the drift problem is caused by anisotropic refractive index change of the beam intersection layer in beam splitter of interferometer.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.48-48
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• 2022

Ethnobotany is an interdisciplinary science at the intersection of botany and ethnology. Currently, there is a sharply increasing need for the study and conservation of traditional knowledge about plants. The loss of traditional sources, knowledge, and practices in using plants is caused by the growth of technologies in all branches of production, widespread urbanization, and globalization of the economy. This study was been conducted to collect and analyze the Koryoins (Koryo saram) traditional ethnobotanical knowledge, living in Uzbekistan, whose number 174,200 people. They are the descendants of Korean immigrants to the Russian Far East, who ended up in Central Asia as a result of the forced resettlement in 1937. In the processing of collected data, four main categories of uses were defined - Alimentary, Medicinal, Household/Handicraft, and Others. For quantitative data analysis, synthetic indices were used - RFC (Relative Frequency of Citation) and CI (Cultural Importance Index), which are commonly applied to assess the importance of plants. The respondents mentioned 72 plants belonging to 28 botanical families. A significant part of them was cultivar plants. The category that had the largest number of plants mentioned by the respondents was the Alimentary use category (51). According to quantitative indices rates, the most important plants are traditionally used for food. A comparison of ethnobotanical knowledge was made with the collected data of this study and Korean traditional knowledge.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.83-92
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• 2007

In 2004, the number of traffic crashes and deaths in Korea are 220,755 and 6,563, respectively. Korea Road Traffic Safety Authority reported that the number of traffic accidents occupies over 25% out of total accidents, and found that traffic crash probability is extremely high at intersections since intersections have various traffic conflict points. A Safety study using Traffic Conflict Technique is much more useful than a study using reported traffic accident data. Existing traffic conflict research hardly considered conflict severity occurring at intersections. So, the study developed new criteria considering conflict severity. Analytic methods precisely detecting crashing points using field surveying data, and applied an application of our new criteria. Opposing left-turn conflict criteria was devided by three groups(high severe conflict, middle severe conflict, and less severe conflict) based on conflict boundary by means of a standard vehicle length. After analyzing field surveying data(3hours), we found totally 41 opposing left-turn conflicts. 3 cases are high severe conflict, and another 10 cases are middle severe conflicts, and the other cases are less severe. Studies related in conflict severity are considerably important to evaluate intersection's detailed safety index, and existing studies(purely conflict counting does not consider severity) have a limitation to clearly determine the level of safety of intersections for an application.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.434-440
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• 2022

The ICAO (International civil aviation organization)recommended the implementation of the GANP (global air navigation plan) for strategic decision-making and air traffic management evaluation. In this study, we proposed a new method for finding the route distance from KPI (key performance indicator) 05 actual route extension presented for air traffic management evaluation. For this purpose, we collected trajectory data for one month and calculated the en-route distances using the methods presented in ICAO and the methods presented by this author. In the ICAO method, the intersection point must be estimated through the equation of a circle for radius 40 NM and the equation of a straight line for an inner and outer point close to a circle in the track data, and four flight distances are calculated to calculate the en-route distance. In the method presented in this study, two flight distances are calculated without estimating the intersection point to calculate the en-route distance. To determine the error between the two methods, we used the performance evaluation index RMSE (root mean square error) and the determination factor R² of the regression model.

• Korean Journal of Social Welfare Studies
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• v.44 no.1
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• pp.61-87
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• 2013

The main purpose of this paper is to analyze the quality of life of poor women. This study utilized data combined KLIPS with Time Use Survey for an analysis and analyzed time at the intersection of the class and gender. With discretionary time as center, this study investigated poverty status from the quality of life. And in order to make comparison more clearly, object was classified into 4 groups; non-poor male, poor male, non-poor female and poor female. Study results are as follows; First of all, poor women had the shortest discretionary time among all the groups and also had highest poverty rate of living quality. And this study found that deprivation of non-poor female headed householder is serious. Second, analysis of inequality level between and within groups through Theil index indicated that gender influence in poor strata was 3 times higher than that of non-poor strata. This study found that poor women experienced mixed exclusion at the point where gender and class crossed. And this study also has a meaning that an empirical analysis was conducted through above matters on secondary poverty and hidden poverty of poor women which existing researches were unable to discover.

• Health Policy and Management
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• v.23 no.2
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• pp.124-131
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• 2013

Background: This study aimed to measure the opportunity income by identifying the economic length of stay (ELOS) which is the intersection point of daily revenue and cost on appendectomy and pneumonia cases. Methods: The research subjects were 460 patients of appendectomy and 606 patients of pneumonia, discharged from a general hospital between July 1, 2009 and June 30, 2010. ELOS calculated with both of total revenue on diagnosis-related group (DRG) and fee-for service (FFS). The cost is calculated by activity-based costing system of the hospital. Results: Average length of stay (ALOS) of appendectomy was 4.48 days and its average revenue per case were 1,710,215 (1,989,105) won by DRG (FFS). The variable cost was 491,262 won which was 28.7% (24.7%) of DRG (FFS) total revenue. And 97.2% of the total variable cost was incurred within 2 days from admission. The ELOS was 4 (5) days in DRG (FFS). Shortening three days (two days) would increase opportunity income 52.0% (82.2%) in DRG (FFS). ALOS of pneumonia case was 4.86 days and its average revenue per case were 489,448 (761,426) won by DRG (FFS). The variable cost was 27,230 won which was 5.6% (3.6%) of DRG (FFS) total revenue. Thirty-eight point nine percent of the daily variable cost was incurred in discharge date. The ELOS was 2 (4) days in DRS (FFS). Shortening three days (one day) would increase opportunity income 27.6% (37.2%) in DRG (FFS). Conclusion: The ELOS would be used by strategic index for achieving minimum profit and developing the ways to get there. But we also should not pass over that the opportunity income obtained by the reducing ALOS may cause some problem of quality.

• International Journal of Highway Engineering
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• v.18 no.3
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• pp.95-107
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• 2016

PURPOSES : This study compared two measures of traffic flow effectiveness on roads with roundabouts and signalized intersections and determined the more appropriate measure. METHODS : In addition to average delay time, the conventionally used measure, average travel time was introduced to measure traffic flow effectiveness because it is able to be obtained through field survey and reflect different travel distances and speed limits of roundabouts and signalized intersections. Using the two measures, roundabouts and signalized intersections were compared through simulations in terms of traffic flow effectiveness. RESULTS : For one-way single-lane roads, the two measures indicated consistent results that roundabouts were more effective than were signalized intersections when the traffic volume was less than 300 vphpl but vice versa when it exceeded 450 vphpl; however, the measures yielded inconsistent results when the volume was 350~400 vphpl. For one-way double-lane roads, the two measures indicated consistent results that roundabouts were more effective than were signalized intersections when the volume was less than 200 vphpl but vice versa when it exceeded 400 vphpl; however, the measures yielded inconsistent results when the volume was 250~350 vphpl. The results obtained using the two measures differed substantially for double-lane roads because behaviors such as weaving and lane changing at roundabouts are more common in double-lane roads than in single-lane roads. CONCLUSIONS : The average delay time would be lower on roads with roundabouts, but average travel time would be lower on roads with signalized intersections. Thus, evaluating the relative effectiveness of roads with roundabouts and signalized intersections by using average delay time alone would be inappropriate, whereas using average travel time as the evaluation index would yield fairer results.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.125.2-125.2
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• 2011

We are developing medium resolution cross-dispersed silicon grisms in the near IR region ($1.45{\sim}5.2{\mu}m$). The grisms will be installed in MIMIR, a multifunction instrument at the Lowel Observatory, USA. The two devices are designed to cover H and K band and L and M band simultaneously. Our goal is to make grism with R=3000 at 1.2 arcsec slit. The Silicon has high refractive index (n=3.4 at $1.5{\mu}m$) which enhances the resolving power by up to 5 times when compared to conventional material such as BK-7 (n=1.5 at 1.5 ${\mu}m$). The bonded grisms will be installed in a filter wheel for the uses switch from spectroscopic mode to imaging mode easily. Our device is compact and light weighted while it provides a decent resolving power. We produce monolithic grisms using e-beam lithography at the NASA JPL and chemically etching the grooves on the silicon prisms. Moreover, the main-disperser and cross-disperser will be contacted together by direct Si-Si bonding technique and eventually turn into one piece. The bonded pair offers more stability in terms of the layout of the spectrum and removes the Fresnel loss at the intersection of two grisms. We report on the proper wafer bonding steps through this research, and inspected the bonding quality thermally, optically and mechanically.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.5
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• pp.303-313
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• 2021

Recently, quality control of the Liquefied Natural Gas Carrier (LNGC) cargo hold and block-erection interference areas using 3D scanners have been performed, focusing on large shipyards and the international association of classification societies. In this study, as a part of the research on LNGC cargo hold quality management advancement, a study on deep-learning-based scaffolding system 3D point cloud object detection and post-processing were conducted using a LNGC cargo hold 3D point cloud. The scaffolding system point cloud object detection is based on the PointNet deep learning architecture that detects objects using point clouds, achieving 70% prediction accuracy. In addition, the possibility of improving the accuracy of object detection through parameter adjustment is confirmed, and the standard of Intersection over Union (IoU), an index for determining whether the object is the same, is achieved. To avoid the manual post-processing work, the object detection architecture allows automatic task performance and can achieve stable prediction accuracy through supplementation and improvement of learning data. In the future, an improved study will be conducted on not only the flat surface of the LNGC cargo hold but also complex systems such as curved surfaces, and the results are expected to be applicable in process progress automation rate monitoring and ship quality control.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.4
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• pp.78-96
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• 2023

Urban traffic information is collected by various systems such as VDS, DSRC, and radar. Recently, with the development of deep learning technology, smart intersection systems are expanding, are more widely distributed, and it is possible to collect a variety of information such as traffic volume, and vehicle type and speed. However, as a result of reviewing related literature, the performance evaluation criteria so far are rbs-based evaluation systems that do not consider the deep learning area, and only consider the percent error of 'reference value-measured value'. Therefore, a new performance evaluation method is needed. Therefore, in this study, individual error, interval error, and overall error are calculated by using a formula that considers deep learning performance indicators such as precision and recall based on data ratio and weight. As a result, error rates for measurement value 1 were 3.99 and 3.54, and rates for measurement value 2 were 5.34 and 5.07.