• Journal of Communications and Networks
• /
• 제16권2호
• /
• pp.140-145
• /
• 2014

In this paper, we propose an anti-interference cooperative spectrum sharing strategy for cognitive system, in which a secondary system can operate on the same spectrum of a primary system. Specifically, the primary system leases a fraction of its transmission time to the secondary system in exchange for cooperation to achieve the target rate. To gain access to the spectrum of the primary system, the secondary system needs to allocate a fraction of bandwidth to help forward the primary signal. As a reward, the secondary system can use the remaining bandwidth to transmit its own signal. The secondary system uses different bandwidth to transmit the primary and its own signal. Thus, there will be no interference felt at primary and secondary systems. We study the joint optimization of time and bandwidth allocation such that the transmission rate of the secondary system is maximized, while guaranteeing the primary system, as a higher priority, to achieve its target transmission rate. Numerical results show that the secondary system can gain significant improvement with the proposed strategy.

• International Journal of Internet, Broadcasting and Communication
• /
• 제16권1호
• /
• pp.191-202
• /
• 2024

Self-efficacy is a major factor related to performance and needs to be improved in business and education field. This study explains the effectiveness of school career assistance to improve college students' self-efficacy. Furthermore, it demonstrates the moderating effects of grit and regulatory focus (promote and prevention). School career assistance is based on group support, and moderating variables in this paper are individual characteristics. In these group and individual dimensions, if the effectiveness of school career assistance varies depending on individual characteristics, schools will be able to establish self-efficacy improvement strategies more appropriate for individual students. School would understand individual characteristics such as grit and regulatory focus, then could make individual strategy for enhancing self-efficacy and performance. Hence, it is expected that the performance of school and student will improve through the self-efficacy improvement plan presented in this study.

• 한국생물정보학회:학술대회논문집
• /
• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
• /
• pp.331-336
• /
• 2005

Post translational modifications (PTMs) discovery is an important problem in proteomic. In the past, people discover PTMs by Tandem Mass Spectrometer based on ‘bottom-up’ strategy. However, such strategy suffers from the problem of failing to discover all PTMs. Recently, due to the improvement in proteomic technology, Taylor et al. proposed a database software to discover PTMs with ‘topdown’ strategy by FTMS, which avoids the disadvantages of ‘bottom-up’ approach. However, their proposed algorithm runs in exponential time, requires a database of proteins, and needs prior knowledge about PTM sites. In this paper, a new algorithm is proposed which can work without a protein database and can identify modifications in polynomial time. Besides, no prior knowledge about PTM sites is needed.

• Journal of Power Electronics
• /
• 제17권4호
• /
• pp.983-990
• /
• 2017

This paper proposes a model predictive control based on the discrete Lyapunov function to improve the performance of power electronic converters. The proposed control technique, based on the finite control set model predictive control (FCS-MPC), defines a cost function for the control law which is determined under the Lyapunov stability theorem with a control error compensation. The steady state and dynamic performance of the proposed control strategy has been tested under a single phase AC/DC voltage source rectifier (S-VSR). Experimental results demonstrate that the proposed control strategy not only offers global stability and good robustness but also leads to a high quality sinusoidal current with a reasonably low total harmonic distortion (THD) and a fast dynamic response under linear loads.

• 한국자동차공학회논문집
• /
• 제20권6호
• /
• pp.83-91
• /
• 2012

In recent days, the study on hybridization of the heavy-duty is going on, actively. Especially, the improvement of fuel economy can be maximized in the intra-city bus because it drives the fixed route. For developing the hybrid electric intra-city bus, optimized control strategy which is possible to be applied with real vehicle is necessary. If the real-time control strategy is developed based on the HILS, it is possible to verify the real-time ability and fail-safety function which has the vehicle stay in safe state when the functional errors are occurred. In this study, the HILS system of series hybrid electric intra-city bus is developed to verify the real time control strategy and the fail-safety functions. The main objective of the paper is to build the HILS system for verifying the control strategy (rule-based control) which is implemented to reflect the Dynamic Programming results and fail-safety functions.

• 초등상담연구
• /
• 제10권1호
• /
• pp.19-38
• /
• 2011

본 연구는 초등학생의 학업스트레스를 감소시키고 학업스트레스에 보다 효율적으로 대처할 수 있는 능력을 키우기 위한 인지행동적 학업스트레스 대처 프로그램을 개발하여 그 효과를 알아보는데 목적이 있다. 이러한 연구목적을 달성하기 위해 경상남도 소재 Y초등학교 24명의 아동을 각각 훈련집단과 통제집단에 12명씩 임의 배정하여, 매회 40분씩 주 2회, 6주간에 걸쳐 총 12회기로 구성된 프로그램을 실시하였으며 프로그램 실시 전후와 종료 4주 후에 학업스트레스 질문지와 학업스트레스 대처방식 질문지를 실시하여 프로그램의 효과를 평가하였다. 본 연구에서 사용한 프로그램은 먼저 학업스트레스 유발상황 조사지를 제작하여 초등학생들이 흔히 경험하는 학업과 관련된 스트레스상황을 조사하고, 그러한 상황에서 아동들이 경험하는 스트레스를 인식하도록 도와주어 학업스트레스 유발상황에서 나타나는 인지적 왜곡을 수정하여 학업스트레스에 적절하게 대처하는 방법에 초점을 두고 구성하였다. 또한 국가 청소년 위원회에서 위기청소년을 위해 개발한 인지행동 집단상담 프로그램과 학업스트레스를 조절하는데 사용된 기존의 프로그램들을 초등학생에게 적용 가능한 형태로 수정하였다. 본 연구의 결과 인지행동적 학업스트레스 대처훈련은 첫째, 아동들이 학업스트레스 유발상황에서 경험하는 성적, 수업과 공부 및 과제관련 스트레스를 감소시키고 그 효과를 지속시키는 것으로 나타났다. 둘째, 학업스트레스에 대한 대처방식을 유의미하게 변화시키는 것으로 나타났다. 대처방식 중 소극적-회피적 대처와 도움추구적 대처는 유의미하게 변화시키는 것으로 나타났으나 적극적 대처에 미치는 효과는 다소 제한적인 것으로 나타났다.

• Journal of Power Electronics
• /
• 제9권6호
• /
• pp.940-948
• /
• 2009

The main objective of this a paper is to improve the efficiency of permanent magnet synchronous motors (PMSMs) by using an improved direct torque control (DTC) strategy. The basic idea behind the proposed strategy is to predict the impact of a small change in the stator flux amplitude at each sampling period to decrease electrical loss before the change is applied. Accordingly, at every sampling time, a voltage vector is predicted and applied to the machine to fulfill the flux change. The motor drive simulations confirm a significant improvement in efficiency as well as a very fast and smooth response under the proposed strategy.

• Journal of Information Technology Applications and Management
• /
• 제25권3호
• /
• pp.29-41
• /
• 2018

The purpose of constructing university information system is for improvement in diversification and throughput of information, streamlines business processes, rapid exchange of information, sharing of information, decision-making information, and securing educational facilities. Similar to business information technology system, university information system does not have a review system for sharing and overlapping investment of information. Due to the lack of project management for outsourcing and vulnerability of system suitability, system audit is absolutely needed for the university information system. This paper especially focuses on an operational phase in the audit of university information system. Additionally, we proposed operating model and checklists of the university information system based on Management Guidelines of ITIL V3 Operational and Information System. We derived the checklists of operation audit by each domain of service strategy, service design, service transition, service operation, and continual service improvement. As the result, this study appear to have more than average satisfaction the suitability results were.

• 산업경영시스템학회지
• /
• 제41권3호
• /
• pp.83-89
• /
• 2018

In the SW industry, the diversification of global markets and technology trends are changing due to the emergence of new services, and IT companies are in need of strategic change different from the previous one. In this study, SWOT analysis was performed by extracting the internal environmental factors and external environmental factors through the previous studies to improve the project performance competence of small IT companies, and the SWOT Matrix was reconstructed through the pairwise comparison. Based on this, the purpose of this research was to propose the project performance competency improvement plans for small IT companies based on importance and priority, and the following four strategies were derived from the result of SWOT-AHP analysis. SO strategy was drawn in direction to invest R & D in new SW industry to enhance technology competitiveness of SMEs in order to develop SMEs, and in order to secure competitiveness of SW industry, WO strategy is drawn the cultivation of professional technical manpower through SW policy. ST Strategy presented technical management through SW system improvement policy to improve SW environment, and WT Strategy presented awareness training on the construction and necessity of project management system construction. Using the strategies presented in this study, it is expected that the managers of small IT firms will be presented as references to measure the performance competence factors of current organizations and company organizations.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제11권2호
• /
• pp.670-686
• /
• 2017

MapReduce (MRV1), a popular programming model, proposed by Google, has been well used to process large datasets in Hadoop, an open source cloud platform. Its new version MapReduce 2.0 (MRV2) developed along with the emerging of Yarn has achieved obvious improvement over MRV1. However, MRV2 suffers from long finishing time on certain types of jobs. Speculative Execution (SE) has been presented as an approach to the problem above by backing up those delayed jobs from low-performance machines to higher ones. In this paper, an adaptive SE strategy (ASE) is presented in Hadoop-2.6.0. Experiment results have depicted that the ASE duplicates tasks according to real-time resources usage among work nodes in a cloud. In addition, the performance of MRV2 is largely improved using the ASE strategy on job execution time and resource consumption, whether in a multi-job environment.