• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.199-204
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• 2012

The study for developments and economics about the energies from the global warming is very active. For the effective saving and the spanning of the life extension about the 19% rates for the illumination system spending power about the whole electric energies, we proposed the new type of the current control method using a mixing system of the frequency modulation together with the pulse width modulation for the half-bridge power instrument. And we proved the excellence and the stability for our suggested system and analyzed the characteristics.

• Convergence Security Journal
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• v.13 no.4
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• pp.27-32
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• 2013

In this paper, technologies applied to design urination detection device on diaper that issues an alarm signal to guardian within 10~20m are introduced. It features power saving that uses both low power bluetooth v4.0 chip and low-power program scheme that makes sensor and mirco-controller to be sleep mode while data is not receiving from sensor. Urination detection algorithm that utilizes the difference between previous sensing data and current values is used to improve the degree of the detection precision level. The device designed with the suggested technologies shows the performance that is 100ml of the minimum urine amount for detection, more than 90% of urination detection degree, and 100% of wireless communication success rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8B
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• pp.1122-1128
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• 2010

In this paper, we proposed and designed a novel SNA protocol which operates in the way of a server and a client in the power control system. The proposed SNA protocol includes the information about the mode switching, the saving position of context information, the user trigger, and so forth, which are needed in the power management devices. We consider the application of the SNA protocol to the home network, where message flows between the SNA server and the SNA client. To verify the operation of the SNA protocol, the state transition diagrams of the server in the home gateway and the client in the network device are shown. Hence, we can conclude the SNA can operate without malfuction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.3
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• pp.65-70
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• 2023

In recent years, the digital media environment has begun to diversify, with a greater focus being placed on user-centric design. With the development of digital technology, the digital media environment has formed a vast network of information, which supports interactive communication between people, creating a need for user-centric research. Mobile displays, as a representation of the digital media environment, have the advantage of mobility through the use of thin screen displays and low-performance image sensors, which allow for miniaturization and power saving. However, this results in reduced colour accuracy compared to large displays. This study investigates users' colour perception when using dark and light mode mobile displays. Colour perception was measured using a psycho-physical experiment, which controls each colour attribute based on the 12 colours of KS. The results were analysed to determine whether there is a difference in colour perception between dark mode and light mode, and if the difference was statistically significant. Future research directions based on the results are then discussed.

• The Journal of the Korea Contents Association
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• v.12 no.8
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• pp.69-76
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• 2012

This paper proposes an efficient power consumption scheme using sleep mode in home gateway. The scheme by this paper classifies incoming real time packet and non-real time packet in home gateway and delay non-real time packet. Therefore, the home gateway can have longer sleep time because non-real time packet can get additional delay time by proposing mechanism using timer. We use non-preemptive two priority queueing model for performance analysis. As a results, we verify that power consumption of proposed scheme is reduced more than existing scheme by delay of non-real time traffic.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9A
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• pp.884-891
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• 2006

A wireless sensor node is typically battery operated and energy constrained. Therefore it is critical to design efficient power management technique and scheduling technique. In this paper, we propose an OS-level power management technique for energy saving of wireless sensor node, it is called EA-SENTAS (Energy-Aware Sensor Node TAsk Scheduling). It can decrease the energy consumption of a wireless sensor node to use task scheduling technique that shut down components or use low power mode of each component when not needed. Simulation results show that EA-SENTAS saves energy up to 56 percent to compare with conventional duty cycle.

• The Journal of Sustainable Design and Educational Environment Research
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• v.6 no.2
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• pp.25-52
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• 2007

This paper is focused on the economical efficiency of the geothermal heat pump system in school. As the importance of problems of environment and energy becomes larger, the development and distribution of energy-saving technology in the whole nation has become influential. This paper is intended, targeting on school buildings scattered all over the country, to evaluate the introduction and possibility of a terrestrial heat system which is in the first stage of introduction in the country, through energy consumption and efficiency in case where a terrestrial heat system is introduced. To do that, the author performed a qualitative analysis of the heat pump system using various terrestrial heat energy and the system introduced to existing school buildings and, through the analysis, made tentative evaluation on the most environment-friendly and energy saving type system. Also, the author performed simulation analysis using a currently typical school building standard and, on the basis of this result, conducted efficiency analysis of various heat pump systems. The conclusion according to synthetical analysis & evaluation can be summarized as follows. In case a heat pump system is introduced to a school building, it was deemed the investment in the early stage would increase, but the investment could be collected within 5~6 years through reduction of large operation expenses. Also, it was analyzed in case of terrestrial heat contracted heat mode using midnight electric power among heat pump systems, not only early investment but also operation expenses could be reduced to a great extent. Accordingly in case the system using terrestrial heat energy is applied to the school buildings that are to be newly built or repaired in the future, it will provide an object-lesson to students as well as contributing to energy saving.

• KIEE International Transactions on Power Engineering
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• v.3A no.4
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• pp.222-230
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• 2003

This paper presents reference designs for vapor-cooled HTS/Copper leads rated at 25 kA and 40 kA and that satisfy a protection criterion. Each HTS section is cooled by the effluent helium vapor boiling from a 4.2-K bath. Each HTS section is based on a design concept in which a short portion of its warm end (77.3 K) operates in the current-sharing mode; such operation results in a considerable saving for HTS materials required in the HTS section. Two designs of "fully superconducting" vapor-cooled HTS sections, one rated at 25 kA and the other at 40 kA are also presented as comparison bases for the new HTS sections. Each warm end of HTS sections is coupled to an optimal vapor-cooled copper lead rated at the same current as that for the HTS section. The extra coolant required at 77.3 K at the coupling station, an optimal length of the copper section will be shorter than that optimized for helium-vapor cooling between 4.2 K and room temperature.mperature.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.540-550
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• 2016

Since energy efficiency has become a significant concern for network infrastructure, next-generation network devices are expected to have embedded advanced power management capabilities. However, how to effectively exploit the green capabilities is still a big challenge, especially given the high heterogeneity of devices and their internal architectures. In this paper, we introduce a hierarchical power management architecture (HPMA) which represents physical components whose power can be monitored and controlled at various levels of a device as entities. We use energy aware state (EAS) as the power management setting mode of each device entity. The power policy controller is capable of getting information on how many EASes of the entity are manageable inside a device, and setting a certain EAS configuration for the entity. We propose the optimal local control policy which aims to minimize the router power consumption while meeting the performance constraints. A first-order Markov chain is used to model the statistical features of the network traffic load. The dynamic EAS configuration problem is formulated as a Markov decision process and solved using a dynamic programming algorithm. In addition, we demonstrate a reference implementation of the HPMA and EAS concept in a NetFPGA frequency scaled router which has the ability of toggling among five operating frequency options and/or turning off unused Ethernet ports.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.2
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• pp.47-56
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• 2015

In an energy saving server cluster environment, the power modes of servers are controlled according to load situation, that is, by making ON only minimum number of servers needed to handle current load while making the other servers OFF. This algorithm works well under normal circumstances, but does not guarantee QoS under abnormal circumstances such as sharply rising or falling loads. This is because the number of ON servers cannot be increased immediately due to the time delay for servers to turn ON from OFF. In this paper, we propose a new prediction algorithm of the power consumption for improving QoS under not only normal but also abnormal circumstances. The proposed prediction algorithm consists of two parts: prediction based on the conventional time series analysis and prediction adjustment based on trend analysis. We performed experiments using 15 PCs and compared performance for 4 types of conventional time series based prediction methods and their modified methods with our prediction algorithm. Experimental results show that Exponential Smoothing with Trend Adjusted (ESTA) and its modified ESTA (MESTA) proposed in this paper are outperforming among 4 types of prediction methods in terms of normalized QoS and number of good reponses per power consumed, and QoS of MESTA proposed in this paper is 7.5% and 3.3% better than that of conventional ESTA for artificial load pattern and real load pattern, respectively.