• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.622-631
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• 2015

This study was conducted to clarify the distribution and fragmented points of mountain range and to select priority points for restoration by assessment in Daejeon. There were ten Semaek of mountain extended from three Jimaek in Daejeon. As a result of overlapping the main mountain ridge with a network of roads, twelve points out of total thirty-one fragmented points were chosen as practical points for restoration. We developed index and model to assess twelve practical points for restoration. All points were classified into three grades, four points of grade I, five points of grade II and three points of grade III. From this study, we proposed differentiated restoration plan for each grade. Further studies on development of more objective assessment and detailed methodology should be needed to prepare effective restoration plan.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.1
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• pp.73-82
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• 1997

This paper discusses the design and implementation of parabola, lens, and $32{\times}8$ rectangular microstrip patch array antennas at 77GHz for vehicular radar applications. The parabola size was $7{\times}10$ cm and the f/D was 0.263. Open waveguide(WR-12) was utilized as the feed antenna. Two types of lens antennas with f/D=0.5 were investigated ; one was a plano-convex and the other was a double-convex. A patch array antenna was designed using a transmission line model and experimented. Comparing the theoretical values with the measured ones for four antennas, the results were agreed well in 3 dB BW and radiation patterns, while the gain of the patch array antenna was degraded as much as -25 dB due to the feed network and microstrip-to-coax-to-waveguide transition losses.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.1
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• pp.8-17
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• 2014

In this research, we employed various data mining techniques to build predictive models for win-loss prediction in Korean professional baseball games. The historical data containing information about players and teams was obtained from the official materials that are provided by the KBO website. Using the collected raw data, we additionally prepared two more types of dataset, which are in ratio and binary format respectively. Dividing away-team's records by the records of the corresponding home-team generated the ratio dataset, while the binary dataset was obtained by comparing the record values. We applied seven classification techniques to three (raw, ratio, and binary) datasets. The employed data mining techniques are decision tree, random forest, logistic regression, neural network, support vector machine, linear discriminant analysis, and quadratic discriminant analysis. Among 21(= 3 datasets${\times}$7 techniques) prediction scenarios, the most accurate model was obtained from the random forest technique based on the binary dataset, which prediction accuracy was 84.14%. It was also observed that using the ratio and the binary dataset helped to build better prediction models than using the raw data. From the capability of variable selection in decision tree, random forest, and stepwise logistic regression, we found that annual salary, earned run, strikeout, pitcher's winning percentage, and four balls are important winning factors of a game. This research is distinct from existing studies in that we used three different types of data and various data mining techniques for win-loss prediction in Korean professional baseball games.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2039-2044
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• 2016

This study aims to investigate the safety instrument to prepare the policy alternative for social web-board game which will be developed to base on social network in the future although social casino game is not available in Korea now. We reviewed several literature about responsible game system applied to especially U.S. New Jersey, responsible gambling system acted in the being advanced all countries. Game experts built up user protection model as previous work to prepare the law and policy which such a responsible game system will apply for current web-board gaem and future social casino game. As a result, this research revealed that standard of judgement which can identify four kind of addiction danger user group are raised. We expect to help this user protection alternative to provide the law and policy instrument for future social casino game and complement the problem of current web-board enforcement.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.23-29
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• 2002

Five and more leg intersections have been still in operation in many urban areas. The number of conflicts in five leg intersection is more than four leg intersection. The signal timing design in the five leg intersection should be performed not only to reduce delay but also to increase safety. This paper suggests safety enhanced signal phase sequence design of a rotary with five leg intersection such as phase sequence minimizing the number of conflict points at the rotary with five leg intersections and the phase-length-design procedure by utilizing the Traffic Network Study Tool(TRANSYT). Field data was collected from Gonguptap five leg intersection in Ulsan and TRANSYT-7F was applied for signal timing design model. Optimal signal phase length and sequence of TRANSYT-7F is rearranged based on the Principal of "two moving traffic flows per phase". In conclusion, proposed signal phase design increased delay by 6.2% compared with the optimal signal phase of TRANSYT-7F. However, it could decrease the number of conflict in the five leg intersection by 61.5%.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.33-39
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• 2019

In this paper, we propose a parametric model for analyzing the motion information obtained from the acceleration sensors to measure the activity of the human body. The motion of the upper body and the lower body does not occur at the same time, and the motion analysis method using a single motion sensor involves a lot of errors. In this study, the 3-axis accelerometer is attached to the arms and legs, the body's activity data are measured, the momentum of the arms and legs are calculated for each channel, and the linear predictive coefficient is obtained for each channel. The periodicity of the upper body and the lower body is determined by analyzing the correlation between the channels. The linear predictive coefficient and the periodic value are used as data to measure the type of exercise and the amount of exercise. In the proposed method, we measured four types of movements such as walking, stair climbing, slow hill climbing, and fast hill descending. In order to verify the usefulness of the parameters, the recognition results are presented using the linear predictive coefficient and the periodic value for each motion as the neural network input.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.44.4-45
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• 2018

(4179) Toutatis (Toutatis hereafter) is one of the Near-Earth Asteroids which has been studied most rigorously not only via ground-based photometric, spectroscopic, polarimetric, and radar observations, but also via the in-situ observation by the Chinese Chang'e-2 spacecraft. However, one of the most fundamental physical properties, the geometric albedo, is less determined. In order to derive the reliable geometric albedo and further study the physical condition on the surface, we made photometric observations of Toutatis near the opposition (i.e., the opposite direction from the Sun). We thus observed it for four days on 2018 April 7-13 using three 1.6-m telescopes, which consist of the Korean Microlensing Telescope Network (KMTNet). Since the asteroid has a long rotational period (5.38 and 7.40 days from Chang'e-2, Zhao et al., 2015), the continuous observations with KMTNet matches the purpose of our photometric study of the asteroid. The observed data cover the phase angle (Sun-asteroid-observer's angle) of 0.65-2.79 degree. As a result, we found that the observed data exhibited the magnitude changes with an amplitude of ~0.8 mag. We calculated the time-variable geometrical cross-section using the radar shape model (Hudson & Ostro 1995), and corrected the effect from the observed data to derive the geometric albedo. In this presentation, we will present our photometric results. In addition, we will discuss about the regolith particles size together with the polarimetric properties based on the laboratory measurements of albedo-polarization maximum.

• Journal of Information Technology Services
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• v.19 no.6
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• pp.177-189
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• 2020

The OECD has assessed Korea as the third highest in trade facilitation worldwide. The paperless trade of Korea is world class based on uTradeHub : national e-trade service's infrastructure for trade community. Over 800 trade-related document standards provide interoperability of message exchange and trade process automation among exporters, importers, banks, customs, airlines, shippers, forwarders and trade authorities. Most one-to-one unit processes are perfectly paperless & online; however, from the perspective of process flow, there is a lack of streamlining end-to-end trade processes spread over many different parties. This situation causes the trade community to endure repetitive-redundant load for handling trade documents. The trade community has a strong demand for seamless trade flow. For streamlining the trade process, processes with data should flow seamlessly to multilateral parties. Flowing data with an optimized process is the critical success factor to accomplish seamless trade. This study proposes four critical digital trade infrastructures as a platform service : (1) data-centric Intelligent Document Recognition(IDR), (2) data-driven Digital Document Flow (DDF), (3) platform based Digital Collaboration & Communication(DCC), and (4) new digital Trade Facilitation Index (dTFI) for precise assessment of K-Trade Digital Trade Framework. The results of new dTFI analyses showed that redundant reentry load was reduced significantly over the whole trade and logistics process. This study leads to the belief that if put into real-world application can provide huge economic gains by building a new global value chain of the K-trade eco network. A new digital trade framework will be invaluable in promoting national soft power for enhancing global competitiveness of the trade community. It could become the advanced reference model of next trade facilitation infrastructure for developing countries.

• Human Ecology Research
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• v.59 no.3
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• pp.353-367
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• 2021

The purpose of this study was to examine the mediating effect of middle school students'self-deprecation in the relationship between upward social comparison in social network service (SNS) and depression and the moderated mediating effect of cognitive flexibility. The participants were 288 middle school students, in the first to third grades from four middle schools located in Seoul, Gyeong-gi, and Jeonnam. The date were analyzed with descriptive statistics, Pearson's correlation coefficients and the Process Macro Model 4, 1, and 14. The results of this study are as follows. First, an upward comparison in SNS has a significant positive influence on students'depression, and students' self-deprecation of students mediated the relation between two. Second, the level of control, which is a sub-factor of cognitive flexibility, moderated the mediating effect of self-deprecation. That is, if students are more likely to perceive difficult situations as controllable, upward social comparison in SNS mediated by self-deprecation has smaller effect on depression. Based on these results, we suggest practical interventions to reduce depression among middle school students by decreasing upward social comparison in SNS and self-deprecation. In addition, helping students perceive difficult situations as controllable could be another effective way of reducing depression among those students who have a high level of self-deprecation in upward social comparison in SNS.

• Smart Media Journal
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• v.10 no.4
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• pp.102-110
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• 2021

Currently, the advanced construction technology endorsement system is being operated to promote the development of domestic construction technology. We tried to examine the implicit meanings inherent in advanced construction technologies by analyzing the relationship between emerging vocabularies with high importance in relation to the advanced construction technologies endorsed through this system. For this purpose, 918 cases of advanced construction technology information were collected. Based on the endorsed year and summary of the advanced construction technologies, the importance of the emerging vocabularies was measured for each advanced construction technology. And, based on the LDA model, the degree of influence between related vocabularies was evaluated for each of the four topic areas. Topics according to the technical application fields were analyzed. From 1990 to 2021, the trend of changes in highly influential vocabularies by each topic was inferred. In the future, changes in the degree of influence of the topics of environment, machinery, facilities, and maintenance and reinforcement of structures and related technology fields were predicted.