• Journal of the Korea Institute of Building Construction
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• v.18 no.2
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• pp.151-159
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• 2018

Accident rate in the construction industry of South Korea is increasing every year, and it represents the highest percentage among industries. This shows that activities performed to prevent safety accidents in the country are not efficient when it comes to reduce the accident rate. In order to resolve this issue, a model for the prediction of human accidents should be established. In addition, it is required a quantification study based on pattern of human accidents. Therefore, the objective of this study is to quantify uncertainty of human accidents risk and predict how to change in various circumstances by using Monte Carlo Simulation. To achieve the objective, first, pattern of human accidents was defined. Second, insurance claim payout and information of human accidents during 14 years in construction site were collected. Third, descriptive analysis is conducted to determine the characteristics of the accident pattern. Fourth, to quantitatively analyze the pattern of the human accidents, the population of each accident occurrence and payout were estimated. Finally, estimated populations was analyzed according to characteristics of distribution by using Monte carlo simulation. In the future, this study can be used as a reference for developing the safety management checklist in construction site and development of prediction models of human accident.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.4
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• pp.41-49
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• 2008

H.264/AVC supports variable block motion compensation, multiple reference images, 1/4-pixel motion vector accuracy, and in-loop deblocking filter, compared with the existing compression technologies. While these coding technologies are major functions of compression rate improvement, they lead to high complexity at the same time. For the H.264 video coding technology to be actually applied on low-end / low-bit rates terminals more extensively, it is essential to improve tile coding speed. Currently the deblocking filter that can improve the moving picture's subjective image quality to a certain degree is used on low-end terminals to a limited extent due to computational complexity. In this paper, a performance improvement method of the deblocking filter that efficiently reduces the blocking artifacts occurred during the compression of low-bit rates digital motion pictures is suggested. In the method proposed in this paper, the image's spatial correlational characteristics are extracted by using the variable block information of motion compensation; the filtering is divided into 4 modes according to the characteristics, and adaptive filtering is executed in the divided regions. The proposed deblocking method reduces the blocking artifacts, prevents excessive blurring effects, and improves the performance about $30{\sim}40%$ compared with the existing method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1C
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• pp.69-77
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• 2002

Sine digital signal processing for motion pictures requires huge amount of data computation to store, manipulate and transmit, more effective data compression is necessary. Therefore, the ITU-T recommended H.26x as data compression standards for digital motion pictures. The data compression method that eliminates time redundancies by motion estimation using relationship between picture frames has been widely used. Most video conding systems employ block matching algorithm for the motion estimation and compensation, and the algorithm is based on the minimun value of cast functions. Therefore, fast search algorithm rather than full search algorithm is more effective in real time low data rates encodings such as H.26x. In this paper, motion estimation employing the Nearest-Neighbors algorithm is designed to reduce search time using FPGA, coded in VHDL, and simulated and verified using Xilink Foundation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.117-124
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• 2017

A Smart Grid is a system that can efficiently use energy by exchanging real-time information in both directions between a consumer and a power supplier using ICT technology on an existing power network. DR(Demand response) is an arrangement in which electricity users can sell the electricity they save to the electricity market when the price of electricity is high or the power system is crisis. In this study, we developed a power meter data transmission device and power IT system that measure the demand information in real-time using a smart meter and transmit it to a cloud server. The power meter data transmission device developed in this study uses alight sensor connected to a Raspberry Pi 3 to measure the number of blinking lamps on the KEPCO meter per unit of power, in order to provide reliable data without any measurement errors with respect to the KEPCO power data. The power measurement data transmission device uses the standard communication protocol, OpenADR 2.0b. The measured data is transmitted to the power IT system, which consists of the VEN, VTN, and calculation program, via the LTE WiFi communication network and stored in its MySQL DB. The developed power measurement data transmission device issues a power supply instruction and performs a peak reduction DR when a power system crisis occurs. The developed power meter data transmission device has the advantage of allowing the user to adjust it every 1 minute, where as the existing smart metering time is fixed at once every 15 minutes.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.1
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• pp.13-19
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• 2009

A 440MHz wireless and passive surface acoustic wave (SAW) based chemical sensor was developed on a $41^{\circ}YX\;LiNbO_3$ piezoelectric substrate for simultaneous measurement of $CO_2$ gas and relative humidity (RH) using a reflective delay line pattern as the sensor element. The reflective delay line is composed of an interdigital transducer (IDT) and several shorted grating reflectors. A Teflon AF 2400 and a hydrophilic $SiO_2$ layer were used as $CO_2$ and water vapor sensitive films. The coupling of mode (COM) modeling was conducted to determine optimal device parameters prior to fabrication. According to simulation results, the device was fabricated and then wirelessly measured using the network analyzer. The measured reflective coefficient $S_{11}$ in the time domain showed high signal/noise (S/N) ratio, small signal attenuation, and few spurious peaks. In the $CO_2$ and humidity testing, high sensitivity ($2^{\circ}/ppm$ for $CO_2$ detection and $7.45^{\circ}/%$RH for humidity sensing), good linearity and repeatability were observed in the $CO_2$ concentration ranges of $75{\sim}375ppm$ and humidity levels of $20{\sim}80%$RH. Temperature and humidity compensations were also investigated during the sensitivity evaluation process.

• The Journal of the Korea Contents Association
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• v.12 no.11
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• pp.539-548
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• 2012

This study investigated the effects of childcare teachers' role conflict and self leadership on psychological welfare. 64 day care centers located in Seoul and Gyeonggi-do were selected as its subjects and correlations and multiple regression analysis were conducted for 260 childcare teachers from the day care centers. The results of this study were as below. First, in terms of the relationships between childcare teachers' role conflict, self-leadership and psychological welfare, it has been shown that correlations of role stress, role ambiguity, action orientedness, constructive thought, and positive welfare were found in all sub-areas except for the sub-variables of natural reward and negative welfare, whereas correlations of role ambiguity, action orientedness, positive welfare were found also in all sub-areas except for the same sub-variables above. Second, after conducting multiple regression analysis, it has been noted that the variables that affected psychological welfare the most were natural reward followed by role ambiguity and role stress, whereas no statistical significance was found in all other sub-variables.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3127-3137
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• 2018

The study has been focused on identifying the impact of professors' types of leadership on major satisfaction, learning immersion in college students. To achieve this goal, the results of a survey of 543 affiliated students from september 2017 to november were as follows. Data processing has been done using the IBM SPSS statistics 25 program, and t-test and multi-return analysis were performed to determine the characteristics of the survey subjects, to verify the validity and reliability of the survey tools, and to identify differences and influence between factors. First, there was a difference between gender and grade, but by major, there was no difference. Second, learning immersion varies by major, gender and grade. Third, the factors that significantly influence a type of leadership's satisfaction with a major were shown to have a significant impact on vision and sense of duty, individual consideration, situational reward but were not significant in exceptional control by exception. Fourth, the impact of the types of leadership on learning immersion showed that vision and sense of duty, and situational reward, but individual consideration and exceptional control by exception were not significant.

• Korean Journal of Social Welfare Studies
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• v.43 no.2
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• pp.113-139
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• 2012

Under the goal of investigating the difference of staff perceptions in performance evaluations at local self-sufficiency centers, this study set out to examine whether differences would be found between team leaders or those in higher positions and the common staff in criteria, procedures, implementation, rewards, and feedback of performance evaluations. For that purpose, the investigator conducted a survey by mail with staff working for local self-sufficiency centers in 15 cities and provinces across the nation from September 6 to 30, 2010. Of 672 questionnaires that were distributed, 439 were returned. Of these, a total of 432 were used in latent mean analysis. The major findings are as follows: first, the staff at local self-sufficiency centers had a relatively negative perception of performance evaluation in terms of rewards for evaluation results. Secondly, the team leaders or those in higher positions had a more negative perception of performance evaluation in terms of evaluation criteria and rewards for evaluation results than common staff. Based on those findings, the study offered some implications with regard to performance evaluation systems at local self-sufficiency centers.

• Journal of Advanced Navigation Technology
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• v.13 no.6
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• pp.901-906
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• 2009

This paper proposes a call admission control(CAC) method for wireless networks, which is based on the upper bound of a possibility distribution of handoff calls dropping rates. The possibility distribution is estimated in a fuzzy inference and a learning algorithm in neural network. The learning algorithm is considered for tuning the membership functions(then parts)of fuzzy rules for the inference. The fuzzy inference method is based on a weighted average of fuzzy sets. The proposed method can avoid estimating excessively large handoff calls dropping rates, and makes possibile self-compensation in real time for the case where the estimated values are smaller than real values. So this method makes secure CAC, thereby guaranteeing the allowed CDR. From simulation studies we show that the estimation performance for the upper bound of call dropping rate is good, and then handoff call dropping rates in CAC are able to be sustained below user's desired value.

• Journal of Korea Game Society
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• v.16 no.3
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• pp.7-16
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• 2016

This research aims to suggest a gamified smart learning design for Korean EFL young learners' speaking proficiency. Gamification is the use of game-thinking and game mechanics in non-game contexts to engage users in solving problems. Thus, the gamified smart learning as gamification in education is designed not only to elicit students' participation but also to enhance speaking skills. Especially, this research based on the results of a pilot study is focused on easing the burden of homework as well as engaging the speaking English game for the primary students with a relatively short attention span. The game elements utilized in this study are competition, rewards, customized characterization and so on. Kakao Talk is selected for this gamified smart learning research because of its ease of accessibility, and multiple applicable functions for language learning such as voice recording, text messaging and sharing videos or photos. Gamification in smart learning can be a means of productive approach to contemporary EFL teaching and learning.