• Title/Summary/Keyword: Transfer Mobility

Search Result 289, Processing Time 0.031 seconds

Performance analysis of cache strategy for signaling traffic management in wireless ATM network (무선 ATM망에서 신호 트래픽 관리를 위한 기억공간 적재기법의 성능분석)

  • 최기무;조동호
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.23 no.7
    • /
    • pp.1639-1649
    • /
    • 1998
  • For mobile multimedia services, wireless ATM(Asynchronous transfer Mode) network is studied actively. In wireless ATM network, the existing signaling protocols generate heavy traffics for HLR due to the centralized structure that all signaling loads mush be handled in HLR(Home Location Register). Also, centralized structure causes critical connection setup delays. Thus, it is important that wireless ATM reduces the connection setup delays occurred due to high traffic loads of signaling based on distributed processing. In this thesis, we propose a cache strategy for call delivery as well as the cache updates of registration based on ATM multicasting and compares the cost of cache scheme with that of conventional scheme. Our study shows that cache scheme has better performance than the conventional methods in the case that the portable mobility is low and traffic density is large.

  • PDF

Service Delivery Time Improvement using HDFS in Desktop Virtualization (데스크탑 가상화에서 HDFS를 이용한 서비스 제공시간 개선 연구)

  • Lee, Wan-Hee;Lee, Bong-Hwan
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.16 no.5
    • /
    • pp.913-921
    • /
    • 2012
  • The current PC-based desktop environment is being converted into server-based virtual desktop environment due to security, mobility, and low upgrade cost. In this paper, a desktop virtualization system is implemented using an open source-based cloud computing platform and hypervisor. The implemented system is applied to the virtualziation of computer in university. In order to reduce the image transfer time, we propose a solution using HDFS. In addition, an image management structure needed for desktop virtualization is designed and implemented, and applied to a real computer lab which accommodates 30 PCs. The performance of the proposed system is evaluated in various aspects including implementation cost, power saving rate, reduction rate of license cost, and management cost. The experimental results showed that the proposed system considerably reduced the image transfer time for desktop service.

Joint Optimization of Mobile Charging and Data Gathering for Wireless Rechargeable Sensor Networks

  • Tian, Xianzhong;He, Jiacun;Chen, Yuzhe;Li, Yanjun
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.13 no.7
    • /
    • pp.3412-3432
    • /
    • 2019
  • Recent advances in radio frequency (RF) power transfer provide a promising technology to power sensor nodes. Adoption of mobile chargers to replenish the nodes' energy has recently attracted a lot of attention and the mobility assisted energy replenishment provides predictable and sustained power service. In this paper, we study the joint optimization of mobile charging and data gathering in sensor networks. A wireless multi-functional vehicle (WMV) is employed and periodically moves along specified trajectories, charge the sensors and gather the sensed data via one-hop communication. The objective of this paper is to maximize the uplink throughput by optimally allocating the time for the downlink wireless energy transfer by the WMV and the uplink transmissions of different sensors. We consider two scenarios where the WMV moves in a straight line and around a circle. By time discretization, the optimization problem is formulated as a 0-1 programming problem. We obtain the upper and lower bounds of the problem by converting the original 0-1 programming problem into a linear programming problem and then obtain the optimal solution by using branch and bound algorithm. We further prove that the network throughput is independent of the WMV's velocity under certain conditions. Performance of our proposed algorithm is evaluated through extensive simulations. The results validate the correctness of our proposed theorems and demonstrate that our algorithm outperforms two baseline algorithms in achieved throughput under different settings.

An Exploratory Study on the Use of Care Robots and Devices by Caregivers of Older Adults Residing in Facilities (시설 거주노인 돌봄 제공자의 돌봄 로봇 및 기기 활용에 관한 탐색적 연구)

  • Eun-Young Kwag;Gwi-Ryung Son Hong
    • The Journal of Korea Robotics Society
    • /
    • v.18 no.4
    • /
    • pp.392-402
    • /
    • 2023
  • The purpose of this study was to conduct an exploratory and descriptive survey study design to examine 1) the physical difficulty by care task, 2) overall occupation-related physical burden by the characteristics of caregivers and care receivers, and 3) the level of help by the use of care robots and devices among formal caregivers working in facilities for older adults. In this study, 308 formal caregivers working in facilities were recruited from 8 nursing homes and 5 geriatric hospitals between Aug. 2021 and Sept. 2022 in South Korea. There were significant differences in ADLs between nursing homes and geriatric hospitals: eating, dressing, hygiene, transfer to bed, transfer to the toilet and walking. For each care item, the items the caregivers had the most difficulty ranked first were bathing, excretion assistance, and mobility support. The difference in occupation-related physical burden according to general characteristics was found to have statistically significant differences in female and bad perceived health. Among the 205 caregivers who had experience using care robots and devices, pressure ulcer prevention was the most experienced one, and those also were the most helpful and exercise aids were the least helpful. In order to reduce the physical burden on care providers, it is necessary to develop and introduce a care robots centered on the care site. Furthermore, national level public support systems are required to enable facilities to actively utilize care robots and devices.

A Study on the Demand for Equipent Development in Nursing (간호기기 개발수요 조사연구)

  • Chang, Soon-Book;Kim, Eui-Sook;Whang, Ae-Ran;Kang, Kyu-Sook;Suh, Mi-Hae
    • The Korean Nurse
    • /
    • v.35 no.2
    • /
    • pp.71-91
    • /
    • 1996
  • The objectives of thes study were to identify the need for equipment development in nursing, and to determine the priorities for that development. The study was descriptive study done between March 2 and May 30, 1995, in which the subjects, including 421 patients, 223 family members, and 198 nurses from neurosurgery, orthopedic, rehabilitation medicine, internal medicine and intensive care units of nine general hospitals in Seoul, completed a questionnarie developed by the research team. The questionnaire consisted of 35 open and closed questions. Data was analyzed using frequencies and percentages. The results ware summarized as follows: 1) The average age of the nurses was 27.9 years, 48% of the patients were between 20 and 40 years of age, and 17% were over 60. The average lingth of experience for the nurse subjects was four years five months with 36.9%. having over five years experience. The most frequent diagnoses of patients were spinal disc(35.9%), internal medicine disease(26.0%), cerebral vascular accident(16.6%) and spinal cord injury(10%) 2) Many of the nurses(96.4%) reported deficiencies with existing equipment and 96.5% of the nurses, but only 79.8% of the patients, nurses' time. Further, 82.3% of the nurses and 75.8% of the patients felt that the development of new equipment would lead to a decrease in the cost of nursing care. 3) Nurses felt that the greatest areas of inconvenience were patient feeding(71.7%), hygiene(71.2%), caring for a patient confined to bed(70.7%), patient clothing(67.2%), mobility transfers(63.5%) and urinary elimination(52.0%). However, patients and family members listed the following as being the most inconvenient: urinary elimination(58.7%), Hygiene(50.5), feeding(48.4%), mobility transfers(47.1%) and bed care(45.2%). 4) Generally the nurses listed more inconveniences and patients and family members listed more demands for the development of equipment. These included utensils with large handles, and regulators for tube feedings; mattresses that provide for automatic position change and massage, which have patient controlled levers and a place for bed pan insertion; automatic lifts or transfer from bed to wheelchair; equipment to facilitate washing and oral hygiene as well as equipment that will allow patients with spinal cord injuries easy access to showers; a bed pan/urinal for women that is comfortable and effective from which urine can be measured and disposed of easily; disposable dressing sets and tracheostomy care sets and a convenient way of measuring changes in wound size; a safe delivery system for oxygen, a variety of mask sizes and better control of humidity, tracheal material than at present, as well as a communication system for patients with tracheostomies; clothing that will allow access to various parts of the body for treament or assessment without patients having to remove all of their clothing; and finally a system that will allow the patient to control lighting, telephones and pagers. Priority areas for equipment development reported by the nurses were, urinary elimination(58. 7%), hygiene(50.5%), feeding(48.4%), mobility transfers(47..1%), bowel elimination(40.8%). Those reported by the patients family members were feeding(71.7%), hygiene(70.0%), bedcare(70.7%), clothing(67.2%), mobility transfers(63.6%), urinary elimination(52.9%) and bowel elimination(50.5%) Altogether, nurses, patients and family members listed the following as priorities; clothing (178), bed care(144), urinary elimination(92), environment(81), hygiene(70). Further, a health professional forum listed urinary elimination, oxygen delivery, medication delivery, mobility transfers, bed care and hygiene in that order as priority areas. From this study it can be concluded that the first need is to develop equipment that will address the problems of urinary elimination. To do (l)This nurses who are interested in equipment development should organize an equipment development team to provide a forum for discussion and production of equipment for nursing.

  • PDF

Physics-Based SPICE Model of a-InGaZnO Thin-Film Transistor Using Verilog-A

  • Jeon, Yong-Woo;Hur, In-Seok;Kim, Yong-Sik;Bae, Min-Kyung;Jung, Hyun-Kwang;Kong, Dong-Sik;Kim, Woo-Joon;Kim, Jae-Hyeong;Jang, Jae-Man;Kim, Dong-Myong;Kim, Dae-Hwan
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.11 no.3
    • /
    • pp.153-161
    • /
    • 2011
  • In this work, we report the physics-based SPICE model of amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) and demonstrate the SPICE simulation of amorphous InGaZnO (a-IGZO) TFT inverter by using Verilog-A. As key physical parameter, subgap density-of-states (DOS) is extracted and used for calculating the electric potential, carrier density, and mobility along the depth direction of active thin-film. It is confirmed that the proposed DOS-based SPICE model can successfully reproduce the voltage transfer characteristic of a-IGZO inverter as well as the measured I-V characteristics of a-IGZO TFTs within the average error of 6% at $V_{DD}$=20 V.

Falls Risk Factors of Inpatients (입원환자의 낙상 위험 예측 요인)

  • Kim, Eun-Kyung;Lee, Jae-Chang;Eom, Mi-Ran
    • Journal of Korean Academy of Nursing
    • /
    • v.38 no.5
    • /
    • pp.676-684
    • /
    • 2008
  • Purpose: The purpose of this study was to identify the risk factors for falls and to suggest data for developing a program for preventing falls. Methods: This was a case-control study in five university hospitals and a general hospital. In total, 216 patients over the age of 18 yr admitted from January 1 to December 31, 2007 participated. One hundred eight patients with experience of falling were matched by gender, age level, diagnosis, and length of stay with 108 patents with no experience of falling admitted on the same unit. A quality assurance coordinator nurse in each hospital examined 35 fall risk factors developed by researchers. Results: In acute hospitals, history of falls, orientation ability, dizziness or vertigo, general weakness, urination problems, transfer/mobility difficulty, walking dependency, impatience, benzodiazepines, diuretics, and vasodilators showed significance on adjusted-odds ratios for fall. Logistic regression analysis was performed to elucidate the factors that influence falls. The probability of falls was increased by dizziness/vertigo, general weakness, and impatience/agitation. Conclusion: This finding can be used as a useful resource in developing nursing intervention programs to predict and prevent the falls of inpatients.

The Effect of Thermal Annealing Process on Fermi-level Pinning Phenomenon in Metal-Pentacene Junctions

  • Cho, Hang-Il;Park, Jin-Hong
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.290.2-290.2
    • /
    • 2016
  • Recently, organic thin-film transistors have been widely researched for organic light-emitting diode panels, memory devices, logic circuits for flexible display because of its virtue of mechanical flexibility, low fabrication cost, low process temperature, and large area production. In order to achieve high performance OTFTs, increase in accumulation carrier mobility is a critical factor. Post-fabrication thermal annealing process has been known as one of the methods to achieve this by improving the crystal quality of organic semiconductor materials In this paper, we researched the properties of pentacene films with X-Ray Diffraction (XRD) and Atomic Force Microscope (AFM) analyses as different annealing temperature in N2 ambient. Electrical characterization of the pentacene based thin film transistor was also conducted by transfer length method (TLM) with different annealing temperature in Al- and Ti-pentacene junctions to confirm the Fermi level pinning phenomenon. For Al- and Ti-pentacene junctions, is was found that as the surface quality of the pentacene films changed as annealing temperature increased, the hole-barrier height (h-BH) that were controlled by Fermi level pinning were effectively reduced.

  • PDF

Layer Controlled Synthesis of Graphene using Two-Step Growth Process

  • Han, Jaehyun;Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2015.08a
    • /
    • pp.221.2-221.2
    • /
    • 2015
  • Graphene is very interesting 2 dimensional material providing unique properties. Especially, graphene has been investigated as a stretchable and transparent conductor due to its high mobility, high optical transmittance, and outstanding mechanical properties. On the contrary, high sheet resistance of extremely thin monolayer graphene limits its application. Artificially stacked multilayer graphene is used to decrease its sheet resistance and has shown improved results. However, stacked multilayer graphene requires repetitive and unnecessary transfer processes. Recently, growth of multilayer graphene has been investigated using a chemical vapor deposition (CVD) method but the layer controlled synthesis of multilayer graphene has shown challenges. In this paper, we demonstrate controlled growth of multilayer graphene using a two-step process with multi heating zone low pressure CVD. The produced graphene samples are characterized by optical microscope (OM) and scanning electron microscopy (SEM). Raman spectroscopy is used to distinguish a number of layers in the multilayer graphene. Its optical and electrical properties are also analyzed by UV-Vis spectrophotometer and probe station, respectively. Atomic resolution images of graphene layers are observed by high resolution transmission electron microscopy (HRTEM).

  • PDF

Development of Patient Classification System based on Nursing Intensity in Stroke Unit (뇌졸중 전문치료실의 간호강도에 근거한 환자분류도구 개발)

  • Kim, Eunjung;Kim, Heejung;Kim, Miyoung
    • Journal of Korean Academy of Nursing Administration
    • /
    • v.20 no.5
    • /
    • pp.545-557
    • /
    • 2014
  • Purpose: The purpose of this study was to develop a patient classification system based on nursing care intensity for patients with acute stroke-related symptoms and verify its validity and reliability. Methods: Data were collected between November, 2013 and February, 2014. The verification for content validity of the patient classification system was conducted by a group of seven professionals. Both interrater reliability and concurrent validity were verified at stroke units in tertiary hospitals. Results: The intensive nursing care for acute stroke patients consisted of 14 classified domains and 56 classified contents by adding 'neurological assessment and observation' and 'respiratory care': 'hygiene', 'nutrition', 'elimination', 'mobility and exercise', 'education or counselling', 'emotional support', 'communication', 'treatment and examination', 'medication', 'assessment and observation', 'neurological assessment and observation', 'respiratory care', 'coordination between departments', and 'discharge or transfer care'. Each domain was classified into four levels such as Class I, Class II, Class III, and Class IV. Conclusion: The results show that this patient classification system has satisfactory validity for content and concurrent and verified reliability and can be used to accurately estimate the demand for nursing care for patients in stroke units.