• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.2
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• pp.36-43
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• 2009

In this paper, we propose a Cooperative Routing using ARQ-based Transmission (CRARQ) in Mobile Ad-hoc Wireless Sensor Networks (MAWSN). The goals of the CRARQ are to improve both the efficiency of transmission and the reliability of transmission together. The main features and contributions of the proposed CRARQ for supporting these goals are as follows. First, CRARQ uses a reactive concept to construct a route from a source to a destination. Second, CRARQ chooses the most stable relay at each hop along the route by mobility-based strategy. Third, cooperative transmission using the ARQ technique which can improve reliability is used at each hop to send data packets from source to destination. Finally, we present a theoretical analysis model for the proposed CRARQ. The performance evaluation of our protocol is implemented via simulation using Optimized Network Engineering Tool (OPNET) and analysis. The results of both simulation and analysis show that CRARQ achieves the improved packet delivery ratio (PDR) and outage probability.

• Journal of Convergence for Information Technology
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• v.8 no.2
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• pp.233-238
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• 2018

SMEs and small enterprises are making various attempts to manage SMEs in terms of equipment, safety and energy management as well as production management. However, SMEs do not have the investment capacity and it is not easy to build a smart factory to improve management and productivity of SMEs. In this paper, we propose a smart factory construction algorithm that partially integrates the factory equipment currently operated by SMEs. The proposed algorithm supports collection, storage, management and processing of product information and release information through IoT device during the whole manufacturing process so that SMEs' smart factory environment can be constructed and operated in stages. In addition, the proposed algorithm is characterized in that central server manages authentication information between devices to automate the linkage between IoT devices regardless of the number of IoT devices. As a result of the performance evaluation, the proposed algorithm obtained 13.7% improvement in the factory process and efficiency before building the Smart Factory environment, and 19.8% improvement in the processing time in the factory. Also, the cost of input of manpower into process process was reduced by 37.1%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4509-4514
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• 2010

In this thesis, the effect of switch maintenance improvement is confirmed after testing and operating the switch monitoring system that were researched and developed originally in order to improve method of electric switch maintenance. However, as in an automatic interlocking station where a ground crew was not placed, repair and inspection could not be carried out until the maintenance person comes in case of switch problems or maintenance. In order to improve this issue, control module was installed in a monitoring system which can communicate through a data radio to a remote computer. Thus, the monitoring device can receive control information which a remote computer commands during the operation of switches. Afterward, it shows information on the real-time status of swith, in particular, anomaly situation through user interface after the switch is operated. By improving performance of the monitoring system in this way which can be managed and controled at a remote place, the prompt countermeasure system in case of disruption will be built and as a result, efficiency and convenience of maintenance improvement will be expected to increase.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.85-89
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• 2019

Cell-free protein synthesis utilizes the translational machinery in a cell extract. Unlike the conventional cell-based expression methods, not being affected by the conditions for cell growth, cell-free protein synthesis enables flexible manipulation of individual factors affecting the efficiency protein biosynthesis. However, the high cost and low stability of the energy sources to regenerate ATP have limited the use of cell-free synthesis for large-scale production of recombinant proteins. One of the approaches to address this problem is to use glucose as an alternative energy source to regenerate ATP through the glucose-metabolizing pathways in a cell extract. In this study, in an attempt to improve the efficiency of ATP regeneration by reinforcing oxidative phosphorylation process, we supplemented with cellular lipids to a glucose-fueled reaction mixture for cell-free protein synthesis. As a result of the lipid supplementation, the productivity of chloramphenicol acetyltransferase in a cell-free synthesis system using glucose increased more than 6 fold compared to when the lipid was not supplemented.

• Journal of Adhesion and Interface
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• v.23 no.2
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• pp.17-24
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• 2022

Colloidal quantum dots (QDs) have gained attention for applications in quantum dot light emitting diodes (QLEDs) due to their high photoluminescence quantum yield, narrow emission spectra, and tunable bandgap. Nevertheless, non-radiative recombination induced by electron and hole imbalance deteriorates the device efficiency and stability. To overcome the problem, researchers have been trying to enhance hole transport properties of hole transporting layers (HTL) and/or slow down the electron injection in electron transport layer (ETL). Here, we summarize two approaches: i) development of interfacial materials between QD and ETL (or HTL); ii) engineering of HTL by blending or multi-layer approaches.

• Journal of Navigation and Port Research
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• v.43 no.4
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• pp.256-263
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• 2019

The trade volume of Northeast Asian countries is increasing and with the advent of the 4th revolutionary era, minimizing the logistics costs of firm is becoming an important competitive factor. With respect to this, in 2006, the government introduced a certified Integrated logistics firm system to improve the competitiveness of local logistics firms and reduce the logistics costs of firms. They argued that the certified Integrated logistics firm system increased the reliability of logistics firms and increased the efficiency of the logistics industry. On the other side, they argue that the system puts a burden on firms and becomes a big business-oriented market consolidation. This study analyzed the efficiency of Warehousing firms using DEA model. The CCR, BBC efficiency and RTS (return to scale) of 15 Warehousing firms were evaluated. This study also suggested the Warehousing firms which can be benchmarked based on analyzed information.

• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.81-88
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• 2020

In this study, an attempt was made to prepare an effective human rights sensitivity education plan for nursing students. This study was before and after a non-equal control group that identified human rights sensitivity and patient rights awareness. As a result of the study, the human rights sensitivity of the subjects averaged 40.22 out of 90 points. The effect on human rights sensitivity through case-based human rights sensitivity education showed that students who received training to improve case-based human rights sensitivity improved human rights sensitivity and patient rights awareness than those who did not(t=2.765,p=.006, t=-5.768,p=.000). As a result of this study, it is considered that the foundation of the curriculum to improve the human rights sensitivity of nursing students should be prepared. We propose a later study on the relationship between clinical practice and human rights sensitivity.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.37-44
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• 2010

The mobility is one of the most important factor for mobile IPTV. However, mobility is highly vulnerable to eavesdropping and unauthorized access. Generally mobility of mobile services is based on handover techniques. But we showed that mobile IPTV must use other techniques to confirm mobility. In this paper, we analyzed security of wibro mobile IPTV from the viewpoint of mobility. We considered DCAS host must include new addresses of mobile devices. We analyzed total number of authentication for the proposed method. So we showed that proposed method was more efficient than wibro-mobile IPTV. We compared the security of our proposal to the security requirements of TTA.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.4 s.23
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• pp.15-20
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• 2006

This study developed integration control system that improve efficiency and give flexibility of smoke control system and can improve prevention of disasters performance. The reliable each kind sensor and of integration control system was developed by establishing the specifications, algorithms and constructing engineering data. More correct and reliable control function of optimization can be obtained by the central control from integration control system rather than the existent individual control. This sees to do to impose flexibility to smoke control system. Also, this will provide the basics of integration control system and ability security of smoke control system and can construct smoke control system of performance based.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.1-4
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• 2019

Edge Computing 환경에서는 데이터 처리와 시스템 제어를 위한 별도의 서버가 존재하지 않는다. 서버를 통한 중앙통제 방식이 아닌 Edge computing에 사용된 IoT기기들이 연동되어 데이터 분산 처리와 연산을 통해 전체 시스템이 동작된다. 이러한 Edge computing 시스템 구조 특성상 전체 시스템이 과부하를 피하기 위해 각 IoT 기기에서 동시다발적으로 감지되는 실시간 상황 정보를 효율적으로 처리 하여야한다. 이에 따라 실시간 상황 정보를 효율적으로 처리하거나, 다양한 데이터 분석처리 알고리즘들이 연구 개발되어 데이터 처리에 적용되어 왔다. 하지만 데이터의 정보 흐름과 타입에 초점을 맞춘 것이 아니라 예상분석 및 획일화된 알고리즘을 통해서 분석되기 때문에 해당 플랫폼이 주로 지향하는 데이터 형식에 맞지 않으면 성능저하를 수반하며 사용에 제약이 많은 문제점이 있다. 따라서 본 논문에서는 IoT 환경에서 실시간 반응성 향상을 목표로 오픈소스 기반 스트림 데이터 처리 방법에 대한 비교 분석과 Fast-reaction을 위한 데이터 처리 도구 비교 분석을 연구를 진행한다.