• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.469-476
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• 2021

The purpose of this study is to explore the predictors of academic probation in college. Especially, this study focused on student engagement variables among the predictors of academic probation in college. Student engagement variables include hours of absence from class and numbers of log to LMS(Learning Management System) and in extracurricular program system during four weeks after the opening of a course and the numbers of faculty counseling. GPA(grade Point Average) is a dependent variable and GPA of prior semester is a control variable in this study. 17,261 student data were collected for the study. Linear regression model and logistic regression model analyses were conducted in the study. The finding showed that the hours of absence from class and numbers of log in extracurricular program system during four weeks after the opening of a course predicted academic achievement of college students. The result also indicated that hours of absence from class and numbers of log-ins to LMS(Learning Management System) and in extracurricular program system during four weeks after the opening of a course were the predictors of academic probation in college. This study will contribute to investigate indicators of students with low academic performance and to provide proper support for underachievers.

• Smart Media Journal
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• v.12 no.11
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• pp.154-164
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• 2023

The Construction Technology Information System collects, processes, and provides the public with free of charge 16 types of construction technology-related texts or index information, such as construction standards, construction practices, and construction reports, required at construction sites to enhance domestic construction technology. This study judged that user satisfaction could be increased if the budget was allocated first to the most effective construction technology information DB establishment. For each type of construction technology information, the level of satisfaction felt by the population for the quantity provided and the value of use according to the acquisition and utilization of information were investigated. Reliability between independent variables and dependent variables through a multiple regression analysis process to identify how the demographic characteristics of the population affect user satisfaction and the factors that affect the use value of information for each type of construction technology information. and the correlation was analyzed. The correlation between the demographic characteristics of respondents and users' satisfaction with the provided quantity was generally low, but construction experience, age, etc. were found to have an effect on satisfaction with the provided quantity. In particular, among the demographic measurement items of respondents, the more construction experience they had, the higher their satisfaction level with the quantity provided of low-level technical standards, and it was analyzed that older age had an impact on satisfaction with the quantity provided for small and medium-sized business support information.

• Journal of Sericultural and Entomological Science
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• v.51 no.1
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• pp.15-19
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• 2013

Antheraea pernyi silkworm is one of typical wild silkworms, which spins a tawny color cocoon. The cocoon has been used as a resource for textile material due to strong chemical stability and good mechanical properties. In this study, to increase the solubility efficiency of A. pernyi silk fibroin, the composition of dissolution solvent were examined. Calcium chloride tertiary system, normally used for dissolution of Bombyx mori silk fibroin, does not act on A. pernyi silk fibroin. Calcium nitrate system dissolves A. pernyi silk fibroin, and calcium nitrate ethanol system do more easily than calcium nitrate system. Amino acid composition of A. pernyi silk fibroin obtained after dissolution is mainly composed of alanine, glycine, and serine. A. pernyi silk fibroin would be used for non-textile applications near future.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.617-623
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• 2016

Recently, IoT technology has been applied to the control of appliances in the home, and information about temperature, humidity, etc. is collected and the application of the system to control the indoor environment automatically is increasing. Currently, the network configuration of IoT devices is mainly used to connect IoT devices to the Internet through wireless gateways. Since such a method is dependent on a gateway, there are limitations in providing various services. Therefore, this paper proposes an independent method of gateway by using IoT network without using gateway by applying long distance wireless communication technology. IoT devices using the proposed long distance wireless internet technology can connect to a remote server and provide mobility that can not be supported by existing methods, thereby providing more various services. The performance evaluation of the proposed network configuration method is compared with the delay time and the amount of data generated in the existing network method constituted by the gateway and the proposed network configuration method respectively. Experimental results show that the proposed method decreases the delay time and the amount of data generated by the gateway.

• Journal of KIISE
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• v.44 no.6
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• pp.601-606
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• 2017

Recently, we have frequently encountered flying drones with the growth of drone industry. However, it is difficult for a driver to stabilize the motor speed of drones, since the voltage of a Lithium polymer battery used in drones may suddenly drop or rise when its power is exhausted. The instability of the motor speed precludes the drone from maintaining a flight altitude, so that the fuselage of a drone performs ascending and descending repeatedly. For solving this problem, existing techniques either add a compensator considering voltage drop of battery or change the control model. Since these techniques use hardware-implemented modules or depend on motor type and experimental results, there is a problem that new suitable modules should be implemented in accordance with the used motor of the fuselage. For solving this problem, in this paper, we implement a motor speed controller in the firmware of drones by considering voltage drop of battery to enhance drone flight stability.

• Journal of Korea Multimedia Society
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• v.11 no.10
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• pp.1376-1384
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• 2008

Numerous researches on network self-configuration have been conducted on Wireless Sensor Network (WSN) and Ad Hoc network but the results have not been applied yet for factory automation. This paper presents development of intelligent process management systems conducting process monitoring and control irrelevant to physical position of a plant operator. The systems are indispensable for diagnosis of rotating machines which cannot exploit wired network. The system was implemented in a Personal Digital Assistant (PDA) using Bluetooth communication protocol. When a mobile terminal reaches to communication range of the process management server, the server detects the mobile terminal to reconfigure plant network automatically. The server authenticates a user of the terminal to download and installs monitoring and control program considering authorized level of the user. If the terminal leaves communication range of the server, it deletes the node from the network and removes the program automatically to save resources and prevent security problems such as missing terminal. Operation of developed functions was verified in a testbed emulating steel-making plant.

• The KIPS Transactions:PartD
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• v.17D no.6
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• pp.471-480
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• 2010

The purpose of this study is to explore determinants which affect the significant increase in the user acceptance of smart phone. This study also analyzes the effect of each variable on the actual acceptance by empirical methods. In this study, first, the system quality and the service quality are defined as independent variables based on developed IS success model of DeLone & McLean(2003). Second, we proposed the research model by providing trust and perceptual immersion as intermediate variables, and user satisfaction and actual use as dependent variables by the proceeding research for accepting information technology and new service. Third, the statistical analysis is conducted by surveying to 200 smart phone users for verifying a validity of research models and hypotheses. As a result, almost hypotheses are accepted in confidence interval except for the hypothesis between security and trust variable.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.2
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• pp.63-77
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• 2022

Our aim was to reduce estimation errors of a wind velocity model used as an early warning system for weather risk management in the agricultural sector. The Rural Development Administration (RDA) agricultural weather observation network's wind velocity data and its corresponding estimated data from January to December 2020 were used to calculate linear regression equations (Y = aX + b). In each linear regression, the wind estimation error at 87 points and eight time slots per day (00:00, 03:00, 06:00, 09.00, 12.00, 15.00, 18.00, and 21:00) is the dependent variable (Y), while the estimated wind velocity is the independent variable (X). When the correlation coefficient exceeded 0.5, the regression equation was used as the wind velocity correction equation. In contrast, when the correlation coefficient was less than 0.5, the mean error (ME) at the corresponding points and time slots was substituted as the correction value instead of the regression equation. To enable the use of wind velocity model at a national scale, a distribution map with a grid resolution of 250 m was created. This objective was achieved b y performing a spatial interpolation with an inverse distance weighted (IDW) technique using the regression coefficients (a and b), the correlation coefficient (R), and the ME values for the 87 points and eight time slots. Interpolated grid values for 13 weather observation points in rural areas were then extracted. The wind velocity estimation errors for 13 points from January to December 2019 were corrected and compared with the system's values. After correction, the mean ME of the wind velocities reduced from 0.68 m/s to 0.45 m/s, while the mean RMSE reduced from 1.30 m/s to 1.05 m/s. In conclusion, the system's wind velocities were overestimated across all time slots; however, after the correction model was applied, the overestimation reduced in all time slots, except for 15:00. The ME and RMSE improved b y 33% and 19.2%, respectively. In our system, the warning for wind damage risk to crops is driven by the daily maximum wind speed derived from the daily mean wind speed obtained eight times per day. This approach is expected to reduce false alarms within the context of strong wind risk, by reducing the overestimation of wind velocities.

• Information Systems Review
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• v.18 no.4
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• pp.69-88
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• 2016

Nowadays, organizations have adopted Smart Work to efficiently manage tasks, such as electronic document approval, customer management, and site inspection, without spatial-temporal constraints. Smartphones, which are commonly used in Smart Work, enable individuals to perform their jobs anytime and anywhere, thus blurring the boundary between work and non-work. To solve the problem of blurred work/non-work boundaries, a construct of self-control and affective factors needs to be considered because business style is changed from command to autonomy in the Smart Work context. Moreover, employees can convey their emotions easily over smartphones. Recent marketing studies have analyzed consumers' behavior based on the combination of cognitive, affective, and behavioral components, and researchers of information systems are also interested in these factors. However, previous research has some limitations, such as not classifying factors into cognitive, affective, and behavioral as well as not covering all three factors. Therefore, we explore the roles of cognitive, affective, and behavioral components in emotional exhaustion and education performance, and conduct a survey on undergraduate and graduate students, who are the major users of smartphones. Findings show that when individuals improve their cognitive capability (self-control) and usage experience (smartphone communication and internet usage), they can decrease emotional exhaustion and increase education performance. In the role of affective capability, increasing education performance is partially accepted. These results imply that organizations should not focus on controlling the usage of smartphones but on promoting appropriate smartphone usage.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1385-1390
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• 2006

외국에서 ASM 모델의 BNR 적용 연구결과를 국내 하수에 적용하기에는 하수농도, 온도, 슬러지농도 등이 국내와는 달라 적용상 무리가 있다. 본 연구에서 BNR 시뮬레이션을 위한 입력 자료로 활용되는 인자들은 IAWPRC task group에서 제안하는 값들을 사용하되 국내 하수성상에서 필요로 하는 인자들은 직접 실험을 통하여 부분적으로 구해냄으로써 모델 시뮬레이션의 신뢰도를 높이고자 하였다. F/M비의 변화량과 1/SRT과의 관계로부터, 종속영양미생물 생산계수 $Y_H$값을 구한결과, 0.40mg VSS/mg COD였다. 이것을 ASM No.2d에 적용하기 위하여 mg cell COD formed/mg COD oxidized 단위로 환산한 결과 0.58을 나타냈다. H 하수처리장의 1차 침전지 하수를 이용하여 호기성상태에서 OUR Test를 통한 미생물에 의한 유기물 섭취시 산소섭취율 변화를 측정하였다. 호기성상태와 무산소상태에서 구한 쉽게 분해되는 용존성유기물(Ss)값을 비교해보면 각각 35.5mg/L와 39.9mg/L로 약간의 차이는 있으나 유사한 값을 보여주고 있다. 시뮬레이션을 위한 동력학적 계수 중 무산소 상태에서 종속영양미생물의 ${\mu}_{max,H}$는 $3.56d^{-1}$로 나타났고, 호기성상태에서는 구하면 ${\mu}_{max,H}$는 $4.2d^{-1}$로 산출되었다. 종속영양미생물의 사멸계수 $b_H$를 구하기 위한 실험에서 초기 OUR의 10%이내가 될 때까지 걸린 시간은 7일정도가 걸렸으며, 사멸률 $b_H$는 $0.043hr^{-1}$로 나타났다. 독립영양미생물의 최대비성장률 ${\mu}_{max,A}$는 최대암모니아 섭취률을 이용하여 구한 결과 $0.65d^{-1}$로 나타났다.EX>$60%{\sim}87%$가 수심 10m 이내에 분포하였고, 녹조강과 남조강이 우점하는 하절기에는 5m 이내에 주로 분포하였다. 취수탑 지점의 수심이 연중 $25{\sim}35m$를 유지하는 H호의 경우 간헐식 폭기장치를 가동하는 기간은 물론 그 외 기간에도 취수구의 심도를 표층 10m 이하로 유지 할 경우 전체 조류 유입량을 60% 이상 저감할 수 있을 것으로 조사되었다.심볼 및 색채 디자인 등의 작업이 수반되어야 하며, 이들을 고려한 인터넷용 GIS기본도를 신규 제작한다. 상습침수지구와 관련된 각종 GIS데이타와 각 기관이 보유하고 있는 공공정보 가운데 공간정보와 연계되어야 하는 자료를 인터넷 GIS를 이용하여 효율적으로 관리하기 위해서는 단계별 구축전략이 필요하다. 따라서 본 논문에서는 인터넷 GIS를 이용하여 상습침수구역관련 정보를 검색, 처리 및 분석할 수 있는 상습침수 구역 종합정보화 시스템을 구축토록 하였다.N, 항목에서 보 상류가 높게 나타났으나, 철거되지 않은 검전보나 안양대교보에 비해 그 차이가 크지 않은 것으로 나타났다.의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주식시장에 적합한 거래전략은 반전거래전략이고, 이 전략의 유용성은 투자자가 설정한 투자기간보다 더욱 긴 분석기간의 주식가격정보에 의하여 최대한 발휘될 수 있음을 확인하였다.(M1), 무역적자의 폭, 산업의 생산