• Title/Summary/Keyword: Coordinator

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MAC Enhancement by Utilizing Multiple Channels in IEEE 802.15.3 High-Rate Wireless Personal Area Networks (IEEE 802.15.3 Wireless PAN의 MAC에서 다중채널의 적용)

  • Lee Byung-Joo;Rhee Seung Hyong;Choi WoongChul;Chung Kwangsue;Lee Jang-Yeol;Cho Jin-Woong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.8A
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    • pp.656-663
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    • 2005
  • This paper presents a multi-channel enhancement scheme for the MAC protocol of IEEE 802.15.3 High-rate WPAN (Wireless Personal Area Network). The current MAC protocol of the IEEE 802.15.3 High-rate WPAN is designed for sharing a single channel among DEVs of a piconet; that is, within a single piconet, PNC prevents interference through MAC layer assignment of time slots to other DEVs using time-division multiple access. When the number of DEVs that communicate with each other frequently, is increased in a single WPAN, the size of the superframe becomes inevitably large, and this may result in a significant throughput drop or a failure to provide QoS guarantee. A multi-channel enhancement scheme for the MAC protocol of IEEE 802.15.3 High-rate WPAN is proposed to significantly increase the aguegate throughput and more reliably provide the QoS guarantees in a piconet

A Minimum Data-Rate Guaranteed Resource Allocation With Low Signaling Overhead in Multi-Cell OFDMA Systems

  • Kwon, Ho-Joong;Lee, Won-Ick;Lee, Byeong-Gi
    • Journal of Communications and Networks
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    • v.11 no.1
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    • pp.26-35
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    • 2009
  • In this paper, we investigate how to do resource allocation to guarantee a minimum user data rate at low signaling overhead in multi-cell orthogonal frequency division multiple access (OFDMA) wireless systems. We devise dynamic resource allocation (DRA) algorithms that can minimize the QoS violation ratio (i.e., the ratio of the number of users who fail to get the requested data rate to the total number of users in the overall network). We assume an OFDMA system that allows dynamic control of frequency reuse factor (FRF) of each sub-carrier. The proposed DRA algorithms determine the FRFs of the sub-carriers and allocate them to the users adaptively based on inter-cell interference and load distribution. In order to reduce the signaling overhead, we adopt a hierarchical resource allocation architecture which divides the resource allocation decision into the inter-cell coordinator (ICC) and the base station (BS) levels. We limit the information available at the ICC only to the load of each cell, that is, the total number of sub-carriers required for supporting the data rate requirement of all the users. We then present the DRA with limited coordination (DRA-LC) algorithm where the ICC performs load-adaptive inter-cell resource allocation with the limited information while the BS performs intra-cell resource allocation with full information about its own cell. For performance comparison, we design a centralized algorithm called DRA with full coordination (DRA-FC). Simulation results reveal that the DRA-LC algorithm can perform close to the DRA-FC algorithm at very low signaling overhead. In addition, it turns out to improve the QoS performance of the cell-boundary users, and achieve a better fairness among neighboring cells under non-uniform load distribution.

A Study on the Present Status of Clinical Nurses with Expanded Role (진료협력간호사의 운영현황에 관한 연구)

  • Kwon, Young Dae;Sung, Young Hee;Kwon, In Gak;Hwang, Moon Sook
    • Journal of Korean Clinical Nursing Research
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    • v.14 no.3
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    • pp.99-115
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    • 2008
  • Purpose: The purpose for this study was to identify the present state of Clinical Nurses with Expanded Role (CNERs) and provide basic data to refine the roles of CNERs. In this study, CNREs refers to nurses who perform techniques traditionally done by doctors and use titles such as clinical nursing specialist, educator with consultation, research assistant, coordinator, physician assistant and special examiner. Method: This study was conducted from September 1 to November 12, 2007. Data from 684 nurses from 38 hospitals who responded to the questionnaire were analyzed with descriptive statistics using the SPSS 14.0 program. Results: The mean percentage of time spent was, for direct practice, 41.1%, for education and counseling, 22.8%, for consultation and coordination, 10.4%, for research, 6.8%, for administration, 8.9% and for other activities, 10.0%. The most frequently implemented CNERs, activities included consultation and education for patients and their families, counseling by telephone, history taking, physical examination, reading examination results, psychosocial assessment, managing treatment, input of prescriptions, and writing up patient records, Although not frequently performed, nurses in some fields carried out invasive procedures and prescribed medication and laboratory tests. Conclusion: Although the number of hospital CNERs are rapidly increasing, there is still confusion about the title and framework as well as standards. Furthermore, because some nurses are prescribing medication and laboratory tests as well as performing techniques not traditionally done by nurses, there is an absolute need for a legalized system and systematic education system for the safety of patients who are being cared by all CNERs.

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The Development of the Integrated Nursing Practicum Education Matrix based on Learning Outcomes (학습성과기반 단계적 통합간호실습교육 매트릭스 개발)

  • Lee, JuHee;Lee, Taewha;Lee, Hyunkyeong;Kim, Sanghee;Bae, Juyeon;Han, Jeehee;Lee, Kyongeun
    • The Journal of Korean Academic Society of Nursing Education
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    • v.21 no.4
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    • pp.528-539
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    • 2015
  • Purpose: The purpose of this study was to develop an integrated nursing practicum education matrix based on the learning outcomes of each stage. Methods: In this Delphi technique study, 10 experts, consisting of six professors and four nurses, participated in the development of the matrix. The first step was an in-depth review for the composition of the questionnaire and the second step was the Delphi technique. The Delphi survey was conducted two times in order to complete the components of the matrix. The survey data was analyzed for statistical averages and standard deviations to decide the order of priority. Results: According to each stage (i.e. fundamental stage, competent stage, and proficient stage), the matrix was composed of education contents, methods, evaluation methods, and curriculum outcomes. Conclusion: The integrated nursing practicum education matrix of Y University was completed. The developed matrix will result in a reduction in the gap between nursing education and clinical practice and an improvement in nursing competency.

Multi-hop Packet Relay MAC Protocol Considering Channel Conditions in UWB-based WPANs (UWB 기반의 WPAN에서 채널 상태를 고려한 다중 홉 중계 방식의 MAC 프로토콜)

  • Wang Weidong;Seo Chang-Keun;Jeong Soon-Gyu;Yoo Sang-Jo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.11B
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    • pp.792-803
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    • 2005
  • Ultra wide band (UWB) technology will be applied in the high rare wireless personal area networks (WPANs) for its high rate, low power, and innate immunity to multipath fading. In this paper, a power aware multi-hop packet relay MAC protocol in UWB based WPANs is proposed and a power aware path status factor (PAPSF), which is derived from SINR and power resource condition of each device, is used to select a suitable relay node. Compared with relaying by piconet coordinator (PNC), which is easily chosen by other ad hoc routing protocol, the new scheme can achieve hi임or throughput, decrease the time required for transmitting high power signal and we can easily distribute the battery power consumption from PNC to other devices in the piconet to prevent the PNC device using up its battery too fast and finally avoid PNC handover too frequently.

Dynamic Allocation of Channel Times based on Link Quality of HR-WPAN (HR-WPAN에서 링크 상태에 따른 동적 채널 타임 할당 기법)

  • Kang, Jae-Eun;Byun, Sung-Won;Lee, Jong-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.3B
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    • pp.264-273
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    • 2009
  • For IEEE 802.15.3 HR-WPAN, we propose the DABL algorithm that PNC can allocate the channel times to the DEV in super frame in order that system frame throughput is increased and the delay is decreased. In detail, the DABL algorithm allows to dynamically allocate channel time as well as to adaptively apply the modulation and coding scheme based on the link quality of the DEV. In addition, due to the facts that QoS is quite different depending on service types, we provide the DABL algorithm taking into account RT(Real Time) traffic and Non-RT traffic respectively. Finally, we show simulation results of the DABL algorithm compared to the conventional algorithm that the PNC equally allocates channel times to the DEV regardless of the link quality of the DEV.

A risk management methodology for maritime logistics and supply chain applications

  • Mokhtari, Kambiz;Ren, Jun
    • Ocean Systems Engineering
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    • v.4 no.2
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    • pp.137-150
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    • 2014
  • In the marine industry although there has been significant growth towards safety, security and risk assessments or risk-based strategies such as marine insurance and regulations to avoid the risks of damage to properties and the environment or the prospect of premature death caused by accidents etc, the moves toward managing the risks which are linked directly to the business functions and decision making processes have been very slow. Furthermore in the marine industry most perceptions, methodologies and frameworks of dealing with hazards, risks, safety and security issues are for their assessment rather than their management. This trend reveals the fact that in different marine industry sectors such as logistics and shipping there is a lack of coherent risk management framework or methodology from which to understand the risk-based decisions especially for the purpose of design, construction, operation, management and even decommissioning of the marine related applications. On the other hand risk management is not yet viewed holistically in the marine industry in order to, for example, assign a right person, i.e. risk manager, who can act as a coordinator and advisor with responsibilities that are only specific to risk management. As a result this paper, by examining the present physical borders and risk-based activities in the marine industry, aims to propose an appropriate risk management methodology in addition to the emergent role of risk managers which will enable the industry users initially to become familiar with the concept of risk management at its holistic level. In the later stages this eventually can lead to development of risk management capabilities at an exclusive level and its integration into the marine industry functions in future.

Overexpression of Cyclin E and its Low Molecular Weight Isoforms Cooperate with Loss of p53 in Promoting Oncogenic Properties of MCF-7 Breast Cancer Cells

  • Montazeri, Hamed;Bouzari, Saeid;Azadmanesh, Kayhan;Ostad, Seyed Nasser;Ghahremani, Mohammad Hossein
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7575-7582
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    • 2015
  • Cyclin E, a key coordinator of the G1 to S transition in the cell cycle, may be deregulated in several malignancies, including breast cancer. The most significant aberration in cyclin E is its elastase mediated proteolytic cleavage into tumor specific low molecular weight isoforms (LMW-Es). LMW-Es are biochemically hyperactive and biologically drive tumorigenesis in transgenic mouse models. Additionally, expression of LMW-Es has been correlated with poor survival in breast cancer cases. Here we determine whether expression of LMW-Es in a breast cancer cell line that is naturally devoid of these deregulated forms would alter their progression through each phase of the cell cycle. The results revealed that LMW-Es expression resulted in an increased doubling time, concomitant with a predominant increase in the population in the S phase of the cell cycle. Moreover, downregulation of p53 in LMW-Es cells resulted in additional shortening of the doubling time and enrichment of cells in the S and G2/M phases of the cell cycle. Furthermore, expression of LMW-Es sensitized cells to ${\beta}$-estradiol (E2) mediated growth and changed expression patterns of estrogen receptor and Bcl-2. Intriguingly, expression of LMW-Es could surpass anti-apoptotic effects raised by p53 upregulation. Taken together these studies suggest that overexpression of LMW-Es in collaboration with p53 loss results in altered g rowth properties of MCF-7 cells, enhancing the oncogenic activity of these ER positive breast cancer cells.

Motivating Underserved Vietnamese Americans to Obtain Colorectal Cancer Screening: Evaluation of a Culturally Tailored DVD Intervention

  • Lee, Hee Yun;Tran, Marie;Jin, Seok Won;Bliss, Robin;Yeazel, Mark
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.4
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    • pp.1791-1796
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    • 2014
  • Background: Colorectal cancer (CRC) is a leading cause of cancer death among Vietnamese Americans, yet screening remains underutilized. We investigated the effectiveness of a culturally tailored DVD intervention in promoting CRC screening among unscreened Vietnamese Americans age 50 and over. Materials and Methods: Using a community-based participatory research approach, we conducted a trial comparing twenty-eight subjects who received a mailed DVD in Vietnamese, with twenty-eight subjects who received a mailed brochure in Vietnamese. Subjects completed telephone surveys at baseline, One-month, and one-year. The primary outcome was receipt of screening. Secondary measures were participants' knowledge, attitudes, and beliefs about CRC screening. Two focus groups explored the intervention's acceptability and effectiveness. Results: At one year, CRC screening rates of 57.1% and 42.9% were observed in experimental and control group respectively (p=0.42), Subjects in both groups showed increased knowledge about CRC after one month. Focus group findings revealed that the DVD was an effective method of communicating information and would help promote screening. Conclusions: The findings suggest that culturally tailored, linguistically appropriate content is more important than the type of media used. This relatively low intensity, low cost intervention utilizing a DVD can be another useful method for outreach to the often hard-to-reach unscreened population.

The Image Expressions of High-Fashion Snood Coordination (하이패션의 스누드(Snood) 코디네이션에 나타난 이미지)

  • Yang, A-Rang;Lee, Hyo-Jin
    • The Research Journal of the Costume Culture
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    • v.18 no.6
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    • pp.1153-1164
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    • 2010
  • The objective of this study is to analyze the coordination images seen in comprehensive fashion items and their features. This will be done from the viewpoint of both the creativity as well as functional characteristics of items and images. For the method of study, I explored the idea of "snood" style, analyzing its features of 42 pictures appearing from the 2006 S/S to 2010 F/W collection. It is important to note that "snood" style has the characteristics of both a muffler and turtleneck. With looping design connected at both ends, it can be placed around the neck or head, creating the image of wearing a hood. After having examined the selected data and pictures, one can largely divide the exclusive high-fashion image categories into three types: feminine, avant-garde, and finally, active & functional sportive image. First, the orthodox image is widely accepted by most as it has forever evolved within the original tradition of the practically functional muffler(scarf). Second, since the metamorphic image tends to lend itself to free ideas, you can wear a snood around the shoulders like a collar. Worn together with the same type of clothing, the snood can be seen as an effective suit. Third, the aim of image emphasis is to highlight certain points, or make some features more noticeable, as a means of possibly attracting more interest and attention. The image of snood arises out of the use of shapes, colors, and other accessory parts. As mentioned earlier, snood stands out as an independent item instead of just being an accessory to clothing. Its primary function as a style coordinator is emphasized in order to create more distinctive fashion images. Through this study, I thereby intend to provide fashion style data on the latest trends, and high-fashion codes of snood coordination.