• 제목/요약/키워드: Network life time

검색결과 603건 처리시간 0.025초

클러스터 기반 WSN에서 에너지 효율적인 라우팅 기법 (An Energy Efficient Routing Scheme for Cluster-based WSNs)

  • 송창영;김성일;원영진;정용진
    • 전자공학회논문지 IE
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    • 제47권3호
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    • pp.41-46
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    • 2010
  • 무선 센서 네트워크는 다수의 센서들로 구성되며 일단 배치되면 전원의 교환 충전이 어렵기에 한정된 센서의 배터리를 효율적으로 이용하여 전체 네트워크의 수명을 최대한 길게 하는 것이 중요한 문제이다. 네트워크를 계층적으로 분할하여 관리하는 클러스터링 기법으로 대표적인 LEACH 프로토콜은 전체 네트워크의 수명을 연장시키기 위한 좋은 방법 중 하나이며 셋업과 안정 상태로 분할되는 라운드 단위로 구성된다. 본 논문에서는 셋업 단계 자체를 최소화하여 셋업 단계 시 소비하는 에너지를 절약하며 데이터의 특성을 고려할 수 있는 비교 기법을 적용하여 에너지 효율성을 높이는 방법을 제안한다. 본 논문에서 제안한 방식을 적용하여 시뮬레이션 수행한 결과 기존 LEACH에 비해 시간 흐름에 따른 생존 노드 수가 증가하였으며 노드의 평균 에너지 소비량도 감소함을 확인하였다.

Diabetes Detection and Forecasting using Machine Learning Approaches: Current State-of-the-art

  • Alwalid Alhashem;Aiman Abdulbaset ;Faisal Almudarra ;Hazzaa Alshareef ;Mshari Alqasoumi ;Atta-ur Rahman ;Maqsood Mahmud
    • International Journal of Computer Science & Network Security
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    • 제23권10호
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    • pp.199-208
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    • 2023
  • The emergence of COVID-19 virus has shaken almost every aspect of human life including but not limited to social, financial, and economic changes. One of the most significant impacts was obviously healthcare. Now though the pandemic has been over, its aftereffects are still there. Among them, a prominent one is people lifestyle. Work from home, enhanced screen time, limited mobility and walking habits, junk food, lack of sleep etc. are several factors that have still been affecting human health. Consequently, diseases like diabetes, high blood pressure, anxiety etc. have been emerging at a speed never witnessed before and it mainly includes the people at young age. The situation demands an early prediction, detection, and warning system to alert the people at risk. AI and Machine learning has been investigated tremendously for solving the problems in almost every aspect of human life, especially healthcare and results are promising. This study focuses on reviewing the machine learning based approaches conducted in detection and prediction of diabetes especially during and post pandemic era. That will help find a research gap and significance of the study especially for the researchers and scholars in the same field.

Formation of Resilience in the Context of Volunteer Activities Using Information and Communications Technology

  • Lazarenko, NataLiia;Sabat, Nataliia;Sabat, Nadiia;Sylenko, Nadiia;Rundong, Wang;Duchenko, Anna;Shuppe, Liudmyla
    • International Journal of Computer Science & Network Security
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    • 제22권6호
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    • pp.374-381
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    • 2022
  • The article identifies and theoretically substantiates the trends of national resilience in the context of establishing the security of the country and its civilizational subjectivity. The strategy of development of the pedagogical university in the conditions of European integration into the European educational and scientific space based on certain characterological features of the personality of the volunteer in the context of allocation of personal resilience is developed. The analysis of both external and internal challenges and threats to the civilization of the country needs to be understood in the context of economic, socio-political, legal, military-political, spiritual-cultural, educational-scientific and network-information resilience. The concepts of "national resilience" and "national security" are quite close - at first glance, even identical. However, a deeper understanding clarifies the differences: national security is a state of protection of the country identity and its very existence, the realization of its national interests. In turn, resilience is a fairly effective strategy and a fundamental guarantee of national security. At the same time, it is extremely important to understand that both national security as a state and national resilience as a strategy are only means of achieving and developing a strong and humanistic civilizational subjectivity of the country. After all, such subjectivity opens for citizens the opportunity for development, dignified self-realization and a proper life. The restructuring of the volunteer's motivational sphere is due to the dominance of such leading motives, which are focused mainly on maintaining and restoring health, which leads to distorted meaningful life goals: isolation, alienation, passivity, inertia, reduced activity, limited communication, etc. The characteristics of relatively stable human behavior include several primary and secondary properties. The primary (relevant) properties include patience, trust, hope, faith, confidence, determination, perseverance, and love; the secondary - punctuality, neatness, obedience, honesty, loyalty, justice, diligence, thrift, accuracy, conscientiousness, obligation, etc. The restructuring of the volunteer's motivational sphere is due to the dominance of such leading motives, which are focused mainly on maintaining and restoring health, which leads to distorted meaningful life goals: isolation, alienation, passivity, inertia, reduced activity, limited communication, etc. The characteristics of relatively stable human behavior include several primary and secondary properties. The primary (relevant) properties include patience, trust, hope, faith, confidence, determination, perseverance, and love; the secondary - punctuality, neatness, obedience, honesty, loyalty, justice, diligence, thrift, accuracy, conscientiousness, obligation, etc. The use of information and communication technologies in volunteering will contribute to the formation of resilience traits in the structure of personality formation. Directly to the personal traits of resilience should be included methodological competencies, which include methodological knowledge, skills and abilities (ability to define ultimate and intermediate goals, plan, conduct and analyze knowledge, establish and implement interdisciplinary links with disciplines of medical-psychological-pedagogical cycles, etc.). All these competencies form the professional resilience of the volunteer.

데이타 중심 저장 방식의 센서 네트워크를 위한 비균등 영역 분할 기법 (A Non-Equal Region Split Method for Data-Centric Storage in Sensor Networks)

  • 강홍구;전상훈;홍동숙;한기준
    • 한국공간정보시스템학회 논문지
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    • 제8권3호
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    • pp.105-115
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    • 2006
  • 데이타 중심 저장(Data-Centric Storage: DCS) 방식의 센서 네트워크는 같은 값의 데이타를 같은 노드에 저장하기 때문에 센서 네트워크가 확장되거나 같은 값의 데이타가 빈번하게 발생하면 특정 센서 노드에 저장 부하가 집중되어 에너지 효율성이 나빠지는 문제가 발생한다. 기존의 데이타 중심 저장 방식에 대한 연구들은 저장 데이타의 효율적인 관리에만 치우쳐 센서 네트워크의 확장에 따른 에너지 효율성 문제를 고려하지 않았다. 본 논문에서는 다차원 센서 데이타 저장의 효율적인 확장성(Scalability)을 지원하는 비균등 영역 분할(Non-Equal Region Spilt) 기법을 제안한다. 제안한 기법은 센서 네트워크를 센서 노드의 분포에 따라 같은 센서 노드 개수를 갖도록 서로 다른 크기의 영역으로 분할하고 분할된 각 영역 내에서 측정된 데이타를 해당 영역에서 저장 및 관리함으로써 센서 네트워크의 확장에 따른 저장 비용을 줄였다. 또한 분할 영역 개수를 센서 네트워크의 크기와 센서 노드 개수, 센서 데이타 발생량에 비례하게 증가시켜 센서 노드의 에너지 소모를 분산시킴으로써 센서 네트워크의 수명 연장과 확장성을 높였다.

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Corticotropin-Releasing Hormone (CRH)에 의한 인간 위암 세포(MKN-28)의 Migration 증가 (Enhancement of Cell Migration by Corticotropin-Releasing Hormone (CRH) in Human Gastric Cancer Cell Line, MKN-28)

  • 천소영;조대호
    • IMMUNE NETWORK
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    • 제4권4호
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    • pp.244-249
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    • 2004
  • Background: Corticotropin-Releasing Hormone (CRH), an important regulator of stress response, has a potent immunoregulatory effect with the ability to promote the growth of various cancer through CRH receptor type 1 under stress. Although the metastasized cancers through cell migration are more aggressive than the primary cancers, little is known about the effect of CRH on cell migration. Gastric cancer is prone to metastasize to other tissues and it is reported that gastric cancer is response to various stresses such as oxidative stress. Herein, we studied the relationship between CRH and gastric cancer cell migration. Methods: We used gastric cancer cell line, MKN-28 and tested the CRH receptor type 1 expression on MKN-28 by RT-PCR. To examine the change in the ability of migration by CRH in MKN-28, cells were incubated with CRH and then migration ability was measured using a cell migration assay. Results: We confirmed that CRH receptor type 1 was expressed in MKN-28 and HaCaT cells. The migration ability of MKN-28 cells was increased by CRH in a time-, dose- dependent manner. Conclusion: These data suggest that CRH increases migration ability in gastric cancer cell line and that CRH may be a critical regulator in the metastasis of gastric cancer cell.

우리나라 광대역망 구축의 정책기조 (B-ISDN evolution strategy from Korean perspective)

  • 김범환;서승우
    • 기술경영경제학회:학술대회논문집
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    • 기술경영경제학회 1997년도 제11회 하계학술발표회 논문집
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    • pp.286-306
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    • 1997
  • 본고는 정보통신망의 경제적관점을 중점적으로 하여 향후 광대역정보통신망구축이 경제사회에 미치는 영향을 국가경쟁력과 삶의 질 측면에서 분석하였다. 즉 광대역망이 갖는 생산재, 소비재적인 특성과 기술개발과 투자시점간의 시차에 따른 경제적 효과를 고려하였다. 또한 이러한 경제적 접근이외에도 광대역망구축에 대한 현실적인 접근을 위하여 진화단계 특성 등 기술적인 측면을 고려하여 실현가능한 시나리오를 제시하고 그에 따른 영향을 추가하였다. 이에 따라 기술개발 선점에 따른 망구축을 실현하는 기술기반 우위국가는 국가 전반적인 경쟁력을 강화시킬 수 있을 뿐만 아니라 국민의 삶의 질 향상에도 기여할 것임이 제시된다. 또한 우리나라와 같이 기술수준이 낮은 기술기반 열위국가의 경우에 실현가능한 3가지 시나리오를 고려하였다.

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인공신경망을 이용한 계측응력 분류 및 피로수명 평가 (Stress Classification Using Artificial Neural Networks and Fatigue Life Assessment)

  • 정성욱;장윤석;최재붕;김영진
    • 대한기계학회논문집A
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    • 제30권5호
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    • pp.520-527
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    • 2006
  • The design of major industrial facilities for the prevention of fatigue failure is customarily done by defining a set of transients and performing a calculation of cumulative usage factor. However, sometimes, the inherent conservatism or lack of details as well as unanticipated transients in old plant may cause maintenance problems. Even though several famous on-line monitoring and diagnosis systems have been developed world-widely, in this paper, a new system fur fatigue monitoring and life evaluation of crane is proposed to reduce customizing effort and purchasing cost. With regard to the system, at first, comprehensive operating transient data has been acquired at critical locations of crane. The real-time data were classified, by using adaptive resonance theory that is one of typical artificial neural network, into representative stress groups. Then the each classified stress pattern was mapped to calculated cumulative usage factor in accordance with ASME procedure. Thereby, promising results were obtained fur the crane and it is believed that the developed system can be applicable to other major facilities extensively.

Construction of a Transcriptome-Driven Network at the Early Stage of Infection with Influenza A H1N1 in Human Lung Alveolar Epithelial Cells

  • Chung, Myungguen;Cho, Soo Young;Lee, Young Seek
    • Biomolecules & Therapeutics
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    • 제26권3호
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    • pp.290-297
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    • 2018
  • We aimed to understand the molecular changes in host cells that accompany infection by the seasonal influenza A H1N1 virus because the initial response rapidly changes owing to the fact that the virus has a robust initial propagation phase. Human epithelial alveolar A549 cells were infected and total RNA was extracted at 30 min, 1 h, 2 h, 4 h, 8 h, 24 h, and 48 h post infection (h.p.i.). The differentially expressed host genes were clustered into two distinct sets of genes as the infection progressed over time. The patterns of expression were significantly different at the early stages of infection. One of the responses showed roles similar to those associated with the enrichment gene sets to known 'gp120 pathway in HIV.' This gene set contains genes known to play roles in preventing the progress of apoptosis, which infected cells undergo as a response to viral infection. The other gene set showed enrichment of 'Drug Metabolism Enzymes (DMEs).' The identification of two distinct gene sets indicates that the virus regulates the cell's mechanisms to create a favorable environment for its stable replication and protection of gene metabolites within 8 h.

Survey of Visual Search Performance Models to Evaluate Accuracy and Speed of Visual Search Tasks

  • Kee, Dohyung
    • 대한인간공학회지
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    • 제36권3호
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    • pp.255-265
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    • 2017
  • Objective: This study aims to survey visual search performance models to assess and predict individual's visual tasks in everyday life and industrial sites. Background: Visual search is one of the most frequently performed and critical activities in everyday life and works. Visual search performance models are needed when designing or assessing the visual tasks. Method: This study was mainly based on survey of literatures related to ergonomics relevant journals and web surfing. In the survey, the keywords of visual search, visual search performance, visual search model, etc. were used. Results: On the basis of the purposes, developing methods and results of the models, this study categorized visual search performance models into six groups: probability-based models, SATO models, visual lobe-based models, computer vision models, neutral network-based models and detection time models. Major models by the categories were presented with their advantages and disadvantages. More models adopted the accuracy among two factors of accuracy and speed characterizing visual tasks as dependent variables. Conclusion: This study reviewed and summarized various visual search performance models. Application: The results would be used as a reference or tool when assessing the visual tasks.

미끄럼 조건에 따른 로터리 압축기 베인/롤러 표면의 마찰 마멸 특성 (Friction and Wear of the Vane/Roller Surfaces Depending on Several Sliding Condition for Rotary Compressor)

  • 오세두;조성욱;이영제
    • Tribology and Lubricants
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    • 제20권6호
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    • pp.337-342
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    • 2004
  • One of the serious challenges in developing rotary compressor with HFC refrigerant is the prediction of scuffing times and wear amounts between vane and roller surfaces. In this study, the tribological characteristics of sliding surfaces using vane-roller geometry of rotary compressor were investigated. The sliding tests were carried out under various sliding speeds, normal loads and surface roughness. During the test, friction force, wear depth, time to failure and surface temperature were monitored. Because severe wear occurred on vane surface, TiN coating was applied on sliding surfaces to prolong the wear life of vane-roller interfaces. From the sliding test it was found that there was the optimum initial surface roughness to break in and to prolong the wear life of sliding surfaces. Depending on the load and speed, the protective layers, which were composed of metallic oxide and organic compound, were formed on sliding surfaces. Those would play an important role in the amounts of friction and wear between roller and vane surfaces.