• Journal of Communications and Networks
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• v.15 no.5
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• pp.504-513
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• 2013

Communication in delay tolerant networks (DTNs) relies on message transport by mobile nodes, and a correct understanding of the node mobility characteristics is therefore crucial to the design of an efficient DTN routing protocol. However, previous work has mainly focused on uncovering all behaviors of node movement, which is not conducive to accurately detecting the specific movement characteristics of a different node. In this paper, we seek to address this problem based on a consideration of social relationships. We first consider social ties from both static and dynamic perspectives. For a static perspective, in addition to certain accidental events, social relations are considered for a long time granularity and tend to be stable over time. For a dynamic perspective, social relations are analyzed in a relatively short time granularity and are likely to change over time. Based on these perspectives, we adopted different efficient approaches to dividing node pairs into two classes, i.e., familiar and unfamiliar pairs. A threshold approach is used for static social ties whereas a density-based aggregation method is used for dynamic social relationships. Extensive experimental results show that both familiar and unfamiliar node pairs have the same inter-contact time distribution, which closely follows a power-law decay up to a certain point, beyond which it begins to exponentially decay. The results also demonstrate that the inter-contact time distribution of familiar pairs decays faster than that of unfamiliar pairs, whether from a static or dynamic perspective. In addition, we also analyze the reason for the difference between the inter-contact time distributions of both unfamiliar and familiar pairs.

• Research in Community and Public Health Nursing
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• v.31 no.2
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• pp.166-178
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• 2020

Purpose: This study was conducted to examine the effects of the oral care program for improving swallowing function of the elderly using welfare centers on depression, self efficacy, subjective oral health status and swallowing related quality of life. Methods: The intervention in this study was systematically developed through the six stages of Intervention Mapping Protocol (IMP) and was based on Mead's symbolic interaction theory and Bandura's self efficacy theory. A non equivalent control group pre and post-test design was conducted on a total of 37 elderly people (experimental group: 19, control group: 18) from D city. The oral care program was administered to the experimental group once a week for five weeks, totaling five times, and the exact program ran for 50 minutes. The collected data were analyzed using the SPSS/WIN 25.0 program. Results: Following the intervention, subjective oral health score, and swallowing related quality of life were significantly improved in the experimental group. Conclusion: The oral care program presented in this study was found to be effective in increasing subjective oral health status, and swallowing related quality of life for the elderly using welfare centers.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.45-55
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• 2012

The energy efficiency is extremely significant in Wireless Sensor Networks (WSN) which deliver the data sensed in the sensor field, using wireless communications. Under the characteristics of WSN, many MAC protocols employ the Duty Cycle mechanism which continuously operates Wakeup and Sleep periods, for the energy efficiency. However, constant Wakeup period in general Duty Cycle incurs the limited performance of the energy efficiency and the receiving ratio. For addressing this, we design and propose a new scheme called Variable Wakeup Period, considering local traffic conditions. Our scheme enhances receiving ratio by increasing Wakeup period under the high traffic condition, and makes high energy efficiency by decreasing Wakeup period under the otherwise condition. In addition, we evaluate the performance of our scheme by performing the simulation, which experiments the previous synchronous and asynchronous MAC protocols, and which also experiments the same protocols with the proposed scheme, for comparative evaluations.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.4
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• pp.103-112
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• 2004

This paper suggests the way to realize smart card security system by using handwritten signature instead of a password which is traditionally used for user authentication. Because of the familiarity of signature we don't need to try to remember the password and signature is difficult to be used by guess or illegal forced situation. The feature data of handwritten signature is large, so we designed COS which is consist of special commands for processing user's handwritten signature data, user authentication, and basic commands based on ISO 7816-3. Also protocol among user, smart card terminal and DB server is designed. In registration process, the feature data of user signature is saved in both a DB server and a smart card. User authentication is processed by comparing the user signature and the saved feature data in a smart card and in a DB server. And the authentication result and hash value of signature data in DB server are transferred to smart card. During this process the authentication between DB server and user is finished. The proposed security system has more higher level of security in user authentication of smart card and it will Provide safer and more convenient security services.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.4
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• pp.59-71
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• 2001

The Current CORBA shows some limitations for its successful deployment in real time system applications. Recently, OMG adopted Real-Time CORBA specification, which is defined as an extension to CORBA. The goal of the Real-Time CORBA is to provide a standard for CORBA ORB implementations that support 'end to end predictability'. In order to support 'end-to-end predictability', Real Time CORBA specifies many components such as priority model, communication protocol configuration, thread management, and etc. Among them, 'priority model' is the most important mechanism for avoiding or bounding priority inversion in CORBA invocations. In this paper, we present our efforts on a design ,and implementation of the Priority Model in Real-Time CORBA specification. The implementation is done as an extension of omniORB2(v.3.0.0), a popular open source non real time ORB. Experiment results demonstrate that our priority model implementation shows better performance and predictability than the non real-time ORB.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.22-33
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• 2014

As a standard of WMNs, IEEE 802.11s supports two kinds of MAC algorithm: a mandatory EDCA used by IEEE 802.11e and an optional MCCA. While EDCA classifies traffic according to four Access Categories (AC) and offer differentiated service using a classified priority, MCCA can guarantee the specific bandwidth of users with a TDMA-style bandwidth reservation scheme between mesh routers. In case that a flow is VBR traffic of a multimedia application, MCCA has disadvantage that the reserved bandwidth does not be used entirely, though it guarantees required bandwidth of users and fairness using bandwidth reservation with neighbors' node. In this paper, we showed a problem that is wastes the reserved bandwidth when MCCA is enabled and proposed a new scheduling algorithm to prevent waste of bandwidth and to improve network utilization effectively, named Resource Sharing Round Robin (RSRR) scheduling. Finally we showed simulation results that performance of a proposed RSRR is better than the legacy MCCA through NS-2 simulation.

• Journal of Korean Critical Care Nursing
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• v.13 no.1
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• pp.15-26
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• 2020

Purpose : This study aimed to examine factors affecting radiation protective behaviors among emergency room nurses by assessing knowledge, attitude, and environment for radiation protection. Methods : The study employed a cross-sectional design. Subjects were a convenience sample of 129 nurses working in emergency rooms of three general hospitals. Data were collected using self-report questionnaires and analyzed using t-test, ANOVA, Pearson correlation coefficients, and multiple regression. Results : The more the nurses received radiation safety education (t=2.26, p=.026), used protective gear (t=4.40, p<.001), and took health screenings (t=2.65, p=.009), the higher their levels of radiation protection behavior. There were significant relations between radiation protective behaviors and attitude (r=.27, p=.002), and radiation protective behaviors and environment for radiation protection (r=.55, p<.001). The factors affecting radiation protective behaviors were protective environment (β=.53, p<.001), protective attitude (β=.32, p<.001), and the use of protective gear (β=.24, p=.002). Conclusions : The government, hospital administrators, and radiation protection-related organization should adopt the following measures to protect emergency room nurses from radiation: research and development of shield instrument, medical examination for emergency room nurses, protocol development of radiation protection behaviors, extension of education chances of radiation protection, and encouraging the use of protective equipment.

• Therapeutic Science for Rehabilitation
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• v.1 no.2
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• pp.14-22
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• 2012

Introduction : The purpose of scholarly paper is to review of motor learning concepts and to examine in integration of motor learning research finding in occupational therapy services for adults with hemiplegia. Body : The principles of motor learning is stage of learning, type of task, practice and feedback. Depending on stage of learning, therapist need to apply of the principles. In early stage of learning, therapists should be promote patient's awareness about therapeutic goals, task performance environment and how to perform. Whole practice, blocked practice and constant practice improve performance skill. In the latter stage of learning, therapists have to design a intervention protocol for patient to use the implicit feedback. Random practice and open task facilitates performance skills. Conclusion : When establishing the a intervention plan for adults with hemiplegia, therapists should systematically developed the principles of motor learning. Intervention program must be established by applying the principles of motor learning in accordance with the learner's level of task performance, and modified depending on the therapeutic progress.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.189-196
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• 2011

The main issues of the researches are monitoring environment such as weather or temperature variation and natural accident, and sensor gateways which have mobile device, applications for mobile health care. In this paper, we propose the SFMS(Smart Factory Management System) that can effectively monitor and manage a green smart factory area based on M2M service and smart phone with android OS platform. The proposed system is performed based on the TinyOS-based IEEE 802.15.4 protocol stack. To validate system functionality, we built sensor network environments where were equipped with four application sensors such as Temp/Hum, PIR, door, and camera sensor. We also built and tested the SFMS system to provide a novel model for event detection systems with smart phone.

• YAKHAK HOEJI
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• v.37 no.5
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• pp.442-452
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• 1993

Previous experimental and clinical investigations suggest a possible role of new nootropic drug, oxiracetam, in improving cognitive performances in patients affected by organic brain syndrome. In this study, the cognitive and behavioral effects of oxiracetam treatment in patients with clinical symptoms of organic brain syndrome were evaluated. Sixty-six patients were enrolled and assigned to either oxiracetam or placebo, according to a randomized, double-blind design between two patient-groups. Either oxiracetam or placebo was orally given bid for 8 weeks ; daily dose of oxiracetam was 1600mg. All the patients, enrolled in this study, were diagnosed as having mild to moderate cognitive dysfunction as defined by a baseline Mini Mental State ExaminationKorean version (MMSE-K) score between 14 and 25. The patients under-went, at baseline, 4 weeks and 8 weeks after, routine laboratory study (CBC, SMA12, U/A, EKG) and the following neuropsychological tests ; MMSE-K, modified Korean Wechsler Intelligence Scale(MKWIS), Nurses' Observation Scale for Geriatric patients(NOSGER). Fifteen patients of whom were dropped out or excluded from the analysis because of poor compliance or violation of the protocol. Fiftyone patients (aged 54~78 years, male 25, female 26) were analyzed (vascular dementia, 30 ; senile dementia of Alzheimer type, 9 ; mixed type, 5 ; other cause, 7). Statistical analysis of the data demonstrated that the two groups were comparable at baseline. At the end of each study period the oxiracetam group scored significantly better on the majority of the tests evaluating cognitive function, psychometricity and the improvement rating scale of subjective symptoms than placebo group, in which worsening trends or no changes were seen on the whole. No side effects were noted during oxiracetam treatment. The present study, showing positive clinical findings after oxiracetam therapy, confirmed that this drug can be useful pharmacological treatment in organic brain syndrome.