• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.219-228
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• 2007

End-to-end path setup and maintenance are very important for mobile ad-hoc wireless communications, because of the mobility and the limited battery capacity of the nodes in the networks. the AODV routing protocol is the one of mary proposed protocols. However, there are route failure problem with the Proposed protocols between intermediate nodes due to such mobility and exhausted battery characteristics, and this is because only the shortest hop count is considered for the route setup. If route failure happens. Problem such as the waste of bandwidth and the increment of the energy consumption occur because of the discarding data packets in the intermediate nodes and the path re-setup process required by the source node. In addition, it obviously causes the network lifetime to be shortened. This paper proposes a routing protocol based on the AODV routing protocol that it makes use of the remaining energy, signal strength and SNR of the MAC layer resources to setup a path.

• KIEAE Journal
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• v.14 no.2
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• pp.37-46
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• 2014

University buildings are energy-guzzling facility that consume more than 10,000TOE within a campus annually. Even the consumption is on an upswing trend. Behind such high consumption are there cheap power rates for education facility, lack of high-efficiency equipment and ever-increasing use of various information equipment. Being keenly aware that greenhouse gas emission increases due to such rise of energy consumption, the present study carried out a case study. In the case study, the study chose the buildings of E university from top 10 universities that consume energy most in Seoul and examined the current status of their energy consumption and greenhouse gas emission. And then it set the reduction target of greenhouse gas by year. Putting aside a middle and long-termed strategy for later endeavor, it first established the 1st year's implementation plan (2014) for energy saving and greenhouse gas reduction with limited budget and according to greenhouse gas reduction target. The plan is specified as follows. Targets for energy saving are mainly divided into two sectors: machine equipment and electric equipment. 7 ideas were proposed. Three ideas to improve machine equipment are to replace with high-efficiency boilers and chillers and to adjust the position of the cooling tower. By doing so, it was estimated that energy could be saved by 176.34TOE in total and greenhouse gas could be reduced by 370.771t$CO_2$-eq. Four ideas to improve electric equipment include the replacement with LED lights, LED emergency lights and high-efficiency motors and the installation of motion sensors. It was calculated that such replacement could conserve 1,076.08TOE (electric energy) and reduce 2,181.420t$CO_2$-eq (greenhouse gas).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.947-950
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• 2015

In the cause of car accidents in Korea, drowsy driving has shown that it is larger fctors than drunk driving. Therefore, in order to prevent drowsy driving accidents, drowsiness detection and warning system for drivers has recently become a very important issue. Furthermore, Many researches have been published that measuring alpha wave of EEG signals is the effective way in order to be aware of drowsiness of drivers. In this study, we have developed EEG measuring device that applies a signal processing algorithm using the LabView program for detecting drowsiness. According to results of drowsiness inducement experiments for small test subjects, it was able to detect the pattern of EEG, which means drowsy state based on the changing of power spectrum, counterpart of alpha wave. After all, Comparing to the results of drowsiness pattern between commercial equipments and developed device, we could confirm acquiring similar pattern to drowsiness pattern. With this results, the driver's drowsiness prevention system expect that it will be able to contribute to lowering the death rate caused by drowsy driving accidents.

• Journal of Korean Home Economics Education Association
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• v.13 no.3
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• pp.147-160
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• 2001

The purpose of this study is to suggest one of teaching methods through developing a new guideline of the teaching-learning applied the Problem-Based Learning which is derived from the Constructionism. And then we apply this guideline to the class of Home Economics. especially the unit of the Consumption life for investigating the effect of this method in the aspect of improving man-power development as a consumer The results of this study are summarized as follows : First. the class applied a new method of Problem-Based Learning turn out to be more improved in the aspect of consumer consciousness than the untested class going through explanation-based teaching(P< .01). This is, the former result more positive than the latter because the former could be given chances to handle faced problems in class. Second there is no significant difference between the tested class and the untested class in the aspect of consumer skill. This is the fact that the research was conducted in a short Period of time and that the researcher failed to show the suitable stimulation or materials. even though the researcher was well aware of what Problem-Based Learning is. Third students\` evaluation after the test indicates that the tested class not only increase interest in home economics but also help them to take an active Part in class as the main of the class. and that the learning atmosphere is improved and that the effect of learning was also enhanced. Although the aspect of consumer skill is not statistically significant. the result show that adolescents try to Practice their learning from the class in their life.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.340-347
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• 2008

Ubiquitous services are high quality and differentiated services which are provided for users by recognizing the context of users and environmental conditions actively. In this case, context-aware middleware is one of the most important technologies required to implement the ubiquitous services. In this paper, we propose a method for providing ubiquitous services in a specific user space effectively and monitoring human bio-sensors. That is, the design and implementation of intelligent home service middleware and monitoring bio-sensors based on context awareness is discussed here. Context information from various sensors is gathered, and suitable services are inferred and provided to users by the middleware system. In our approach, user services can be modelled easily by using facts and rules, and the system can be extended easily to support various ubiquitous services other than intelligent home services also. The system can be integrated with external applications and legacy systems effectively by using various protocols such as RMI, socket and HTTP, XML and etc. We have designed and evaluated various facts and rules for intelligent home services in real environments. Functionality evaluation with the system shows that ubiquitous services can be provided to users effectively in a home environment.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.4 no.1
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• pp.33-37
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• 2011

Spinoglenoid cyst have been reported in small series in the orthopaedic literature in association with SLAP lesion, which is one of less common causes of shoulder pain. Authors experienced one case of spinoglenoid cyst with SLAP lesion initially missed with ultrasonographic examination and physical examination. This case was confirmed by MRI, EMG and arthroscopic surgery was done. When clinicians cannot find a definite cause of shoulder pain and decreased power of rotator cuff tendon with ultrasonographic examination, they need further study such as MRI and EMG with careful physical examination. Clinicians need to aware of the limitation of ultrasonography for spinoglenoid cyst especially, (1) cyst size is small, (2) location of cyst is too deep to detect and along the scapula spine from SLAP lesion.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.39-48
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• 2013

A cloud system has to deal with highly variable workloads resulting from dynamic usage patterns in order to keep the QoS within the predefined SLA. Aside from the aspects regarding services, another emerging concern is to keep the energy consumption at a minimum. This requires the cloud providers to consider energy and performance trade-off when allocating virtualized resources in cloud data centers. In this paper, we propose a resource provisioning approach based on dynamic thresholds to detect the workload level of the host machines. The VM selection policy uses utilization data to choose a VM for migration, while the VM allocation policy designates VMs to a host based on its service reputation. We evaluated our work through simulations and results show that our work outperforms non-power aware methods that don't support migration as well as those based on static thresholds and random selection policy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.504-521
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• 2016

Recently, energy harvesting technology has been integrated into wireless sensor networks to ameliorate the nodes' energy limitation problem. In theory, the wireless sensor node equipped with an energy harvesting module can work permanently until hardware failures happen. However, due to the change of power supply, the traditional hierarchical network routing protocol can not be effectively adopted in energy harvesting wireless sensor networks. In this paper, we improve the Low-Energy Adaptive Clustering Hierarchy (LEACH) protocol to make it suitable for the energy harvesting wireless sensor networks. Specifically, the cluster heads are selected according to the estimation of nodes' harvested energy and consumed energy. Preference is given to the nodes with high harvested energy while taking the energy consumption rate into account. The utilization of harvested energy is mathematically formulated as a max-min optimization problem which maximizes the minimum energy conservation of each node. We have proved that maximizing the minimum energy conservation is an NP-hard problem theoretically. Thus, a polynomial time algorithm has been proposed to derive the near-optimal performance. Extensive simulation results show that our proposed routing scheme outperforms previous works in terms of energy conservation and balanced distribution.

• Physical Therapy Korea
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• v.9 no.2
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• pp.115-131
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• 2002

Functional electrical stimulation (FES) training of the knee extensors is a useful way to rehabilitate the ability to stand and walk. However, training using FES has not been able to solve the problem of fatigue; clinical application of FES quickly produces muscle fatigue, due to the continuous activation of the muscles of the lower extremity. Therefore, reduction of muscle fatigue is an important factor in increasing the effectiveness of FES training in paraplegia. Intermittent high frequency alternating stimulation is a method that combines the advantages of high frequency (leading to strong muscle contractions) and alternating stimulation (reducing muscle fatigue), thereby continuously strengthening muscles. It is not known whether low frequency simultaneous stimulation results in stronger muscle contraction than high frequency alternating stimulation. This study compared the effectiveness of high frequency alternating stimulation with low frequency synchronized stimulation. Muscle power using FES on the quadriceps of 20 normal subjects were compared. Intermittent high frequency alternating stimulation did not produce more powerful muscle contraction than intermittent low frequency synchronized stimulation, because the muscle characteristics differed individually. Significant individual variation according to muscle characteristics was founded when applying FES. Accordingly, when physical therapists use FES to treat patients, they must be aware of individual variation in muscle characteristics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10A
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• pp.784-795
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• 2009

An accurate positioning estimation in the wireless sensor networks (WSN) is very important in which each sensor node is aware of neighbor conditions. The multi-hop positioning estimation technique is considered as one of the suitable techniques for the WSN with many low power devices. However geographical holes, where there is no sensor node, may severely decrease the positioning accuracy so that the positioning error can be beyond the tolerable range. Therefore in this paper, we analyze error factors of DV-hop and hole effect to obtain node's accurate position. The proposed methods include boundary node detection, distance level adjustment, and unreliable anchor elimination. The simulation results show that the proposed method can achieve higher positioning accuracy using the hole detection and enhanced distance calculation methods compared with the conventional DV-hop.