• Management Science and Financial Engineering
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• v.17 no.2
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• pp.39-62
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• 2011

In wireless sensor network, since each sensor is equipped with a limited power, efficient use of the energy is important. One possible network management scheme is to cluster the sensors into several sets, so that the sensors in each of the sets can completely perform the monitoring task. Then the sensors in one set become active to perform the monitoring task and the rest of the sensors switch to a sleep state to save energy. Therefore, we rotate the roles of the active set among the sensors to maximize the network lifetime. In this paper, we suggest an optimal algorithm for the maximum lifetime coverage problem which maximizes the network lifetime. For comparison, we implemented both the heuristic proposed earlier and our algorithm, and executed computational experiments. Our algorithm outperformed the heuristic concerning the obtained network lifetimes, and it found the solutions in a reasonable amount of time.

• Proceedings of the Safety Management and Science Conference
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• 2013.04a
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• pp.445-456
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• 2013

According to Department of labor guideline "2012-104 (2012.9.26.)" This study is to suggest the basic information and the improvement for the application of risk assessment on a construction site by group interview & survey of construction worker who is the practice of the subject and then numerical analysis about awareness and action plan of Safety and health. The result of group interview and survey of construction worker, most of construction worker feel the danger during the work. Then construction worker analysis results that risk assessment helps to change & raise awareness of safety and reduce an industrial disaster. Easy Safety management activity such as TBM & safety education active will be necessary for safe worksite and then I suggest the TBT(tool box talk) active which combines TBM & safety education.

• Journal of KIISE:Information Networking
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• v.28 no.4
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• pp.517-526
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• 2001

In order to reduce the increasing packet loss rates caused by an exponential increase in network traffic, the IETF(Internet Engineering Task Force) is considering the deployment of active queue management techniques such as RED(Random Early Detection). While active queue management in routers and gateways can potentially reduce total packet loss rates in the Internet, this paper has demonstrated the inherent weakness of current techniques and shows that they are ineffective in preventing high loss rates. The inherent problem with these queue management algorithms is that they all use queue lengths as the indicator of the severity of congestion. In this paper, in order to solve this problem, a new active queue management algorithm called MRED(Modified Random Early Detection) is proposed. MRED computes the packet drop probability based on our heuristic method rather than the simple method used in RED. Using simulation, MRED is shown to perform better than existing queue management schemes. To analyze the performance, we also measure throughput of traffics under the FIFO control, and compared the performance with that of this MRED system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.6B
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• pp.605-614
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• 2009

Existing Internet services were almost supported by the best effort service such as the data transmission service and were allowed the transmission delay and packet loss. However, recent Internet multimedia services such as Internet phone, Internet broadcasting are required a real-time processing and high bandwidth. Therefore, many studies for providing Internet QoS are performed at IETF (Internet Engineering Task Force). As the buffer management mechanism among IP QoS methods, active queue management method such as RED (Random Early Detection) algorithm has proposed. However, RED algorithm has a limitation of usage of an average buffer length and unfairness. So, many algorithms proposed as the modified algorithm of RED. But these modified algorithms also have difficulties to satisfy the requirements of various Internet user QoS. Therefore, in this paper we propose the QoS adaptive AQM (Active Queue Management) algorithm for the multimedia services that request various QoS requirements and present a performance evaluation by the simulations using the ns-2.

• Journal of Information Technology Applications and Management
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• v.28 no.1
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• pp.63-81
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• 2021

The advent of the convergence era led to the convergence of industries while increasing the uncertainty of R&D. R&D uncertainty can be addressed by identifying and addressing industrial innovation patterns, which Neo-Schumpeterian suggested can be identified through the process of identifying the technical characteristics of a particular industry, which can be embodied in the concept of technology trajectory. Thus, this study considered and proposed a method to track the technology trajectory of the convergence industry through topic modeling and patent citation network analysis, and applied it to the micro medical robot industry, which is a representative convergence industry, to track the technology trajectory of active catheter. In particular, it is intended to identify the unique characteristics of the industry by identifying the industry before the promotion of the national-led medical robot industry support policy. Therefore, we tried to understand the innovation pattern of the industry by tracking the technology trajectory of the industry before 2017, the time of full-scale support for the medical robot industry in the United States. Through tracking technology trajectories, the role of each technology classification, the development path, and the knowledge flow between applicants were analyzed empirically. The results of this study are expected to contribute to resolving the remaining uncertainties in the process of establishing an active catheter R&D strategy, one of the leading convergence industries, and furthermore, it is expected to be available for tracking technology trajectories in other industries.

• The Journal of Information Systems
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• v.25 no.4
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• pp.105-119
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• 2016

Purpose The conventional solution methods for production scheduling problems typically focus on the active schedules, which result in short makespans. However, the active schedules are more difficult to generate than the semi active schedules. In other words, semi active schedule based search strategy may help to reduce the computational costs associated with production scheduling. In this context, this paper aims to compare the performances of active schedule based and semi active schedule based search methods for production scheduling problems. Design/methodology/approach Two decoding approaches, active schedule decoding and semi active schedule decoding, are introduced in this paper, and they are used to implement genetic algorithms for classical job shop scheduling problem. The permutation representation is adopted by the genetic algorithms, and the decoding approaches are used to obtain a feasible schedule from a sequence of given operations. Findings The semi active schedule based genetic algorithm requires slightly more iterations in order to find the optimal schedule, while its execution time is quite shorter than active schedule based genetic algorithm. Moreover, the operations of semi active schedule decoding is easy to understand and implement. Consequently, this paper concludes that semi active schedule based search methods also can be useful if effective search strategies are given.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.29-38
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• 2017

This paper presents a study on the state-of-charge (SOC) reference based active cell balancing in real-time. The optimal references of SOC are determined by using the proposed active cell balancing system with the bidirectional DC/DC converters via the dual active bridge (DAB) type. Then, the energies between cells can be balanced by the power flow control of DAB based bidirectional DC/DC converters. That is, it provides the effective management of battery by transferring energy from the strong cell to the weak one until the cell voltages are equalized to the same level and therefore improving the additional charging capacity of battery. In particular, the cell aging of battery and power loss caused from energy transfer are considered. The performances of proposed active cell balancing system are evaluated by an electromagnetic transient program (EMTP) simulation. Then, the experimental prototype is implemented in hardware to verify the usefulness of proposed system.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.11-14
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• 2000

대부분 기존의 Multimedia 시스템은 응용프로그램이나 사용자에 의해 발생되는 Operation 을 수동적인 형태로 처리를 한다. 개발자는 시스템의 목적이나 전략에 따라 시스템을 구성하는 각각의 Module에 대해 작업을 해야 하지만 목적이나 전략이 변경되면 해당되는 각각의 Module을 찾아서 수정을 해야만 한다. 이러한 일은 상당히 번거롭고 Error를 발생시킬 수 있는 가능성을 내포하고 있다. 또한 Multimedia 시스템은 적절한 정보를 관리하고 다양한 응용프로그램을 지원하기 위해서 많은 기능을 가져야 한다. 이 논문은 Event-Condition-Action(ECA) rule의 Active특성을 Multimedia 시스템에 적용하는 것을 제안하고 있다. 이러한 접근 방법을 통해 코드를 효과적으로 관리할 수 있다. 또한, Operation으로부터 rule을 정의하고 관리하는 것을 분리함으로써 Multimedia 시스템에 대해 상위 계층의 새로운 개념을 제시한다. 이렇게 Multimedia 시스템 상에 Active Rule시스템을 계층화시킴으로써 진보된 Multimedia 서비스를 제공할 수 있다. 시스템의 모든 기능은 Event에 의해 발생되고 Rule의 Condition이 만족할 때 해당하는 Rule의 Action이 실행된다. 여기서 제안한 Interactive Group Teaching System (IGTS) 시스템은 Active Rule 시스템인 Active Rule Management System(ARMS) 상에서 구현되었고, Active 속성을 가진 IGTS 을 설계하는 것을 목적으로 하고 있다. 본 시스템은 ECA Rule 개념이 적용 가능함을 보여준다.

• Journal of Families and Better Life
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• v.31 no.3
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• pp.113-124
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• 2013

This study investigated the relationship between school-age children's overt/covert narcissism with self-control and mothers' parenting. The subjects were 517 children in the 5th and 6th grades attending elementary schools located in Daegu and Gyeongbuk Province. The collected data were analyzed by t-test, Pearson's correlation, multiple regressions and SPSS Win 19.0 was used. The results were as follows: (1) School-age children's overt narcissism differed in boys and girls. However, this was not the case for covert narcissism. (2) The overt narcissism of school-age boys and girls was positively correlated with self-control. However covert narcissism was negatively correlated with self-control. (3) The active-responsive and active-restrictive parenting of mothers influenced on the overt narcissism of school-age boys, while the active-responsive parenting of mothers influenced the overt narcissism of school-age girls. Also, the active-responsive and active-restrictive parenting of mothers influenced the covert narcissism of school-age boys, while the active-responsive and passive-permissive parenting of mothers influenced the overt narcissism of school-age girls. (4) The active-restrictive parenting of mothers was the most powerful factor in the overt/covert narcissism of school-age boys and the covert narcissism of school-age girls.

• Journal of Korean Dental Hygiene Science
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• v.3 no.2
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• pp.51-58
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• 2020

Oral examination ensures early detection and treatment of oral diseases and improvement of quality of health-related life. This is imperative as it reduces individuals' dental medical expenses and social costs caused by diseases. However, as the low oral examination acceptance rate continues to be a problem, this study was conducted to identify the factors that influence the oral examination of an economically active population. In this study, 4,836 economically active individuals between the ages of 20 and 65 years were studied using data from the 7th National Health and Nutrition Survey in 2018. Logistic regression analysis was performed to determine the factors influencing demographic and sociological characteristics on oral examination after adjusting for complaints of mastication and speech discomfort. As a result of confirming the factors influencing the oral examination, increase in age tended to be inversely proportional to the oral examination. Income level, type of job, and job position were identified as factors that influenced oral examinations. Compared to the group with a high socioeconomic status, which is represented by a group with a high income level or a stable job type or job position, the group with low economic status was found to have a negative effect on oral examination. Oral management of vulnerable groups, who might not be considered while devising oral health management policies, should be promoted through the development and provision of oral health management policies that consider employment status and environment.