• Title/Summary/Keyword: Mobility Model

Search Result 1,047, Processing Time 0.028 seconds

A Scalable Content-Based Routing Scheme Considering Group Mobility in Tactical Mobile Ad-hoc Networks (군 MANET 환경에서 그룹 이동성을 고려한 확장성 있는 콘텐트 기반 라우팅 기법)

  • Ko, Kwang-Tae;Kang, Kyung-Ran;Cho, Young-Jong
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.5B
    • /
    • pp.721-733
    • /
    • 2010
  • In this paper, we propose a scalable content-based routing scheme for the tactical mobile ad-hoc networks where the nodes usually move together forming a group. Our scheme is classified as a content-based routing scheme based on publish and subscribe model. The nodes compose a cluster according to their position and interest. Our scheme allows multi-level cluster nesting. As a publish/subscribe model does, each node announces its interest to the cluster head who aggregates and announces the interests from cluster members to its neighbor cluster head. Actual data messages are delivered to the end node via cluster header in the reverse direction of the interest announcement. Using Qualnet simulator, we evaluated the performance of our scheme in comparison with two well-known content-based routing schemes. Simulation results show that our scheme maintains higher message delivery ratio as number of nodes increases whereas the two schemes show much lower delivery ratio. In addition, as the group mobility gets faster our scheme incurs less or similar control message overhead compared with the two schemes.

Intergeneration Occupational Mobility Experience of Nurses: Focus on Mother's Experience (간호직을 선택한 자녀를 둔 간호사 어머니의 경험)

  • Kim, Joo Hyun;Nam, Eun Sook;Kil, Myung Sook;Yoon, Sung Ja;Soun, Eun Jin;Park, Eun Young
    • The Journal of Korean Academic Society of Nursing Education
    • /
    • v.20 no.4
    • /
    • pp.523-533
    • /
    • 2014
  • Purpose: The purpose of this study is to analyze how the experiences of nurses influence their role model function when they are mothers of children who in turn have become nurses or nursing students. Method: The subjects of this study were 12 nurses, 8 of their children who became nurses and another 4 children then in training to become one. Data were collected through in-depth personal interviews and subsequently analyzed through a phenomenological approach. Results: Four main themes were identified as follows; 'Persuasion and dissuasion,' 'Proud but still pathetic,' 'As mom and senior nurse' and 'Great to pass it down.' Conclusion: The results of this study show that the nurse as mother could be a positive professional role model for her children. However, they tended to stress the arduous clinical routines and poor work conditions nurses currently experience. Should such routines and conditions improve, mothers who are nurses would be more willing to recommend the nursing profession to their children. Improving the professional environment is thus important because intergeneration nursing mobility provides a reliable resource to recruit qualified and dedicated nursing personnel.

Differential Effects of Local Anesthetics on Rate of Rotational Mobility between Hydrocarbon Interior and Surface Region of Model Membrane Outer Monolayer

  • Chung, In-Kyo;Cha, Seong-Kweon;Chung, Yong-Za;Kim, Bong-Sun;Choi, Chang-Hwa;Cho, Goon-Jae;Jang, Hye-Ock;Yun, Il
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.4 no.1
    • /
    • pp.41-46
    • /
    • 2000
  • Using fluorescence polarization of 12-(9-anthroyloxy)stearic acid (12-AS) and 2-(9-anthroyloxy)stearic acid (2-AS), we evaluated the differential effects of local anesthetics on differential rotational rate between the surface (in carbon number 2 and its surroundings including the head group) and the hydrocarbon interior (in carbon number 12 and its surroundings) of the outer monolayer of the total lipid fraction liposome extracted from synaptosomal plasma membrane vesicles. The anisotropy (r) values for the hydrocarbon interior and the surface region of the liposome outer monolayer were $0.078{\pm}0.001$ and $0.114{\pm}0.001,$ respectively. This means that the rate of rotational mobility in the hydrocarbon interior is faster than that of the surface region. In a dose-dependent manner, the local anesthetics decreased the anisotropy of 12-AS in the hydrocarbon interior of the liposome outer monolayer but increased the anisotropy of 2-AS in the surface region of the monolayer. These results indicate that local anesthetics have significant disordering effects on the hydrocarbon interior but have significant ordering effects on the surface region of the liposome outer monolayer.

  • PDF

A Theoretical Model of Executive Voluntary Turnover (기업내 임원의 자발적 이직에 관한 이론적 모형)

  • Choi, Dongwon
    • Journal of Digital Convergence
    • /
    • v.19 no.8
    • /
    • pp.173-184
    • /
    • 2021
  • For the current organizations, retaining executive members is one of the most important functions of human resource management. Given that importance, although executives' mobility becomes prevalent, most prior studies tended to focus on involuntary turnover of executive members. To fill this gap, the current theoretical paper suggests a model of executive voluntary turnover, drawing on the lierature of employee mobility and entrepreneurship. First, running a new business as a CEO negatively affects prior-firm performance, but collaboration between two firms mitigate the negative association. Second, spin-off positively affects prior-firm performance, but this is weakened as spin-off firm performance decreases. Finally, moving to a competitor negatively, while moving to a collaborator positively affects prior-firm performance.

Development of sound location visualization intelligent control system for using PM hearing impaired users (청각 장애인 PM 이용자를 위한 소리 위치 시각화 지능형 제어 시스템 개발)

  • Yong-Hyeon Jo;Jin Young Choi
    • Convergence Security Journal
    • /
    • v.22 no.2
    • /
    • pp.105-114
    • /
    • 2022
  • This paper is presents an intelligent control system that visualizes the direction of arrival for hearing impaired using personal mobility, and aims to recognize and prevent dangerous situations caused by sound such as alarm sounds and crack sounds on roads. The position estimation method of sound source uses a machine learning classification model characterized by generalized correlated phase transformation based on time difference of arrival. In the experimental environment reproducing the road situations, four classification models learned after extracting learning data according to wind speeds 0km/h, 5.8km/h, 14.2km/h, and 26.4km/h were compared with grid search cross validation, and the Muti-Layer Perceptron(MLP) model with the best performance was applied as the optimal algorithm. When wind occurred, the proposed algorithm showed an average performance improvement of 7.6-11.5% compared to the previous studies.

Real-Time Comprehensive Assistance for Visually Impaired Navigation

  • Amal Al-Shahrani;Amjad Alghamdi;Areej Alqurashi;Raghad Alzahrani;Nuha imam
    • International Journal of Computer Science & Network Security
    • /
    • v.24 no.5
    • /
    • pp.1-10
    • /
    • 2024
  • Individuals with visual impairments face numerous challenges in their daily lives, with navigating streets and public spaces being particularly daunting. The inability to identify safe crossing locations and assess the feasibility of crossing significantly restricts their mobility and independence. Globally, an estimated 285 million people suffer from visual impairment, with 39 million categorized as blind and 246 million as visually impaired, according to the World Health Organization. In Saudi Arabia alone, there are approximately 159 thousand blind individuals, as per unofficial statistics. The profound impact of visual impairments on daily activities underscores the urgent need for solutions to improve mobility and enhance safety. This study aims to address this pressing issue by leveraging computer vision and deep learning techniques to enhance object detection capabilities. Two models were trained to detect objects: one focused on street crossing obstacles, and the other aimed to search for objects. The first model was trained on a dataset comprising 5283 images of road obstacles and traffic signals, annotated to create a labeled dataset. Subsequently, it was trained using the YOLOv8 and YOLOv5 models, with YOLOv5 achieving a satisfactory accuracy of 84%. The second model was trained on the COCO dataset using YOLOv5, yielding an impressive accuracy of 94%. By improving object detection capabilities through advanced technology, this research seeks to empower individuals with visual impairments, enhancing their mobility, independence, and overall quality of life.

Mobility and Safety Evaluation Methodology for the Locations of Hi-PASS Lanes Using a Microscopic Traffic Simulation Tool (미시교통시뮬레이션모형을 이용한 하이패스 차로 위치별 이동성 및 안전성 평가방법 연구)

  • Yun, Ilsoo;Han, Eum;Lee, Cheol-Ki;Rho, Jeong Hyun;Lee, Soojin;Kim, Sang Byum
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.12 no.1
    • /
    • pp.98-108
    • /
    • 2013
  • The number of Hi-Pass lanes became 793 lanes at 316 expressway tollgates in 2011 due to the increase in the Hi-Pass use. In spite of the increase in the number of Hi-Pass lanes, there have been increased potential risks in tollgates where vehicles using a Hi-Pass lane must weave with other vehicles using a TCS lane. Therefore, there is a need for study on the safety in tollgates. To this end, this study aims at developing a methodology to evaluate the performance measures of diverse location countermeasures of Hi-Pass lanes in an efficient and systematic way. This study measured the mobility, safety and the convenience of installation and operation of Hi-Pass lanes using a microscopic traffic simulation tool, the surrogate safety assessment model and survey. In addition, this study aggregated the above three performance indexes using weight factors estimated using the AHP technique. For the test site, Dongsuwon interchange was selected. After building the microscopic traffic simulation model for the test site, the location countermeasures of Hi-Pass lanes applicable to the test site were compared with each other in terms of the mobility, safety and installing and operating convenience. As a result, there has been no apparent difference in mobility index based on delays. However, the countermeasures where Hi-Pass lanes are located in inside lanes generally showed better safety performance based on the number of conflicts. In addition, countermeasures with neighboring Hi-Pass lanes were favorable in terms of the safety and the convenience of installation and operation. The methodology proposed in this study was found to be useful to support decision makings by providing critical and quantitative information regarding the mobility, safety and the convenience of installation and operation.

Effect of Output-conductance on Current-gain Cut-off frequency in In0.8Ga0.2As High-Electron-mobility Transistors (In0.8Ga0.2As HEMT 소자에서 Output-conductance가 차단 주파수에 미치는 영향에 대한 연구)

  • Rho, Tae-Beom;Kim, Dae-Hyun
    • Journal of Sensor Science and Technology
    • /
    • v.29 no.5
    • /
    • pp.324-327
    • /
    • 2020
  • The impact of output conductance (go) on the short-circuit current-gain cut-off frequency (fT) in In0.8Ga0.2As high-electron-mobility transistors (HEMTs) on an InP substrate was investigated. An attempted was made to extract the values of fT in a simplified small-signal model (SSM) of the HEMTs, derive an analytical formula for fT in terms of the extrinsic model parameters of the simplified SSM, which are related to the intrinsic model parameters of a general SSM, and verify its validity for devices with Lg from 260 to 25 nm. In long-channel devices, the effect of the intrinsic output conductance (goi) on fT was negligible. This was because, from the simplified SSM perspective, three model parameters, such as gm_ext, Cgs_ext and Cgd_ext, were weakly dependent on goi. However, in short-channel devices, goi was found to play a significant role in degrading fT as Lg was scaled down. The increase in goi in short-channel devices caused a considerable reduction in gm_ext and an overall increase in the total extrinsic gate capacitance, yielding a decrease in fT with goi. Finally, the results were used to infer how fT is influenced by goi in HEMTs, emphasizing that improving electrostatic integrity is also critical importance to benefit fully from scaling down Lg.