• The Journal of Korean Institute of Communications and Information Sciences
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• 제42권3호
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• pp.604-611
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• 2017

In wireless sensor networks, an energy efficient operation is important since the energy of the sensors is limited. This paper proposes an energy efficient method that reduces a packet generation with Matrix Completion method where sensor value matrix has low-rank and decreases a collision rate and an overhead by transmitting only sensor ID to a time slot corresponding to the sensor value. Computer simulations demonstrates that the proposed method shows 17% of transmission failure and 73% of the packet generation compared to a conventional CSMA/CS. Delay time of transmitting information of the proposed method exhibits 22% of the CSMA/CA and the MSE error after reconstructing sensor values by Singular Value Thresholding(SVT) in Fusion Center is 87% of the CSMA/CA.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.639-641
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• 2002

In this paper, we proposed the multiple access control of RS232C Serial Communications protocol using collision sense method. The communications wires of data transmission and reception are tied together through the buffer each to connect to the multiple communication channels. The hardware interface and control program are designed to build the prototype system and the experimental multiple access communications network is built by multiple PC systems and the transfer completion rate results are shown.

• IE interfaces
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• 제13권1호
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• pp.110-119
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• 2000

Resource-constrained project scheduling is to allocate limited resources to activities to optimize certain objective functions and to determine a start time for each activity in the project such that precedence constraints and resource requirements are satisfied. This study suggests a multi-project scheduling model which can level work loads, make the most of production capacity and restrain the delay of delivery by developing a heuristic algorithm which minimizes the project completion time and maximizes the load rate under resource constraints.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• 제6권1호
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• pp.59-65
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• 1976

The author obtained the following results through the studies on 1012 roentgenograms of lower third molar regions of Korean female; 1. The rate of presence of lower third molars was 78.9 percent. 2. The period that crowns of lower third molars become completed was 16.1 years. 3. The period that completion of apices of lower third molars become completed was over 27 years.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2000년도 추계학술발표논문집 (하)
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• pp.1051-1054
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• 2000

IMT-2000 moving picture messaging service is a primary auxiliary connection service that allows a caller to leave a message when the caller can not complete the call. As the number of service subscriber for wireless communication is dramatically increased, various wireless services as well as simple connection service are requried IMT-2000 moving picture messaging service increases the call completion rate and makes it possible to provide various services.

• Asia pacific journal of information systems
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• 제34권1호
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• pp.248-291
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• 2024

A few years before, MOOCs appeared and developed at a rapid pace. Various MOOC methods, theories, strategies, elements, and techniques were used to improve distance education. In their development, their weaknesses like dropout, low participation, low completion rate, low engagement, and others have emerged that are addressed by recent studies including that of gamified and adaptive gamified MOOCs. This article presents the most important theories, strategies, and elements used in gamification and their usefulness and contribution to MOOCs, with the ultimate goal of proving rich information to researchers, application designers, and practitioners of gamified and adaptive gamified MOOCs.

• Korean Journal of Remote Sensing
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• 제38권6_1호
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• pp.1371-1383
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• 2022

In this study, the amount of coal waste dump was calculated using six Digital Elevation Models (DEMs) produced between 2006 and 2018 in Jangseong-dong, Taebaek-si, Gangwon-do, and the subsidence was observed by applying the Persistent Scatterer Interferometric SAR (PSInSAR) technique on the Sentinel-1 SAR images. As a result of depositing activities using DEMs, a total of 1,668,980 m³ of coal waste was deposited over a period of about 12 years from 2006 to 2018. The observed subsidence rate from PSInSAR was -32.3 mm/yr and -40.2 mm/yr from the ascending and descending orbits, respectively. As the thickness of the waste pile increased, the rate of subsidence increased, and the more recent the completion of the deposit, the faster the subsidence tended to occur. The subsidence rates from the ascending and descending orbits were converted to vertical and horizontal east-west components, and 22 random reference points were set to compare the subsidence rate, the waste rock thickness, and the time of depositing completion. As a result, the subsidence rate of the reference point tended to increase as the thickness of the waste became thicker, similar to the PSInSAR results in relation to the waste thickness. On the other hand, there was no clear correlation between the completion time of the deposits and the rate Of subsidence at the reference points. This is because the time of completion of the deposits at all but 5 of the 22 reference points was too biased in 2010 and the correlation analysis was meaningless. As in this study, the use of DEM and PSInSAR is expected to be an effective alternative to compensate for the lack of field data in the safety management of coal waste deposits.

• The KIPS Transactions:PartC
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• 제16C권3호
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• pp.383-392
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• 2009

Next generation network (NGN) is a packet-based converged network to support session and non-session services in QoS-enabled broadband transport network. QoS based resource control must be defined to support differentiated services for various network users in NGN. This paper defined parallel control schemes for NGN resource control interfaces to minimize session and resource control delays. We simulated the existing and proposed NGN control schemes to measure and analyze control delays and completion ratios. By arrival rate of 120 in two-phase resource control, we checked out that completion ratios of sequential and parallel schemes achieved 100%, and the control delay of parallel scheme was improved by about 21.5% compared to that of sequential scheme.

• The Journal of Fisheries Business Administration
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• 제51권4호
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• pp.1-18
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• 2020

The paper aims to explore existence and degree of remaining fisheries damages after the completion of undertaking the Four Major Rivers Project focusing on the case of Yeongsan river. The paper seeks to show the necessity of consideration of periods of fishery resources recovery in the estimation of ex-post fisheries damages of the project by inferring the analysis of the annual variation of environmental indicators in the river. Therefore, the paper suggests three years of remaining periods of fisheries damages of the project utilizing the variation trend of ex-ante and ex-post annual output data of inland fisheries in Jeonnam province and individual catch of fisheries. In the measurement of the annual degree of fisheries damages during periods of fishery resources recovery, the paper attempts to suggest the method of comparision of day catch data per vessel between ex-ante and ex-post periods of the project, which were investigated by the same institute. Here the paper tries to make correction of ex-post catch data for holding the same catching condition as ex-ante situation by adopting the concept of competitive intensity of catching which was derived from the decreasing rate of number of fishing households in the area of Yeongsan river.

• Tuberculosis and Respiratory Diseases
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• 제70권2호
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• pp.143-149
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• 2011

Background: Stopping medical treatment by tuberculosis (TB) patients prior to completing treatment period is a major concern in private hospitals. We evaluated the impact of public-private mix (PPM) project on increasing treatment success rate of TB in a private tertiary hospital in Korea. Methods: Starting in February 2009, TB patients treated at Dankook University Hospital received health education and case monitoring activities by specially trained public health nurses (PPM project). On a retrospective basis, we reviewed medical records and compared the treatment outcome of TB patients treated under the PPM project (PPM group) to patients treated without the PPM project (control group) between January 2008 and June 2010. In addition, we also evaluated the risk factors treatment non-completion. Results: The number of patients in the PPM group and control group were 123 (85 pulmonary TB and 38 extrapulmonary TB) and 146 (101 pulmonary TB and 45 extra-pulmonary TB), respectively. The PPM group had demographic and clinical findings comparable to those of control group. The PPM group showed a significantly higher treatment success rate (93.5%) compared to the control group (77.9%). However, development of complications, proximity to the hospital, and presence of co-morbid disease did not influence the treatment success rate. Conclusion: The PPM project was effective at increasing the TB treatment success rate. An effort to improve and to expand the PPM project is needed in private Korean hospitals.