• 한국통신학회논문지
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• 제36권2B호
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• pp.111-119
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• 2011

최근에 Green IT 에 대한 관심이 증가함에 따라 네트워크 장치에서 발생하는 에너지의 소비를 줄이기 위한 연구가 지속적으로 증가하고 있다. 본 논문에서는 수면모드 (sleeping mode)를 이용하는 OBS 네트워크에서 트래픽 패턴 및 버스트 어셈블 알고리즘이 에너지 절감율과 지연시간에 미치는 영향을 분석한다. 이를 위하여 OPNET Modeler 를 사용하여 지수 분포와 파레토 분포를 가지는 트래픽 생성 모델과 시간 및 길이 기반의 버스트 어셈블 알고리즘을 수행하는 라우터 모델을 구현하고 시뮬레이션을 수행한다. 구현된 시뮬레이터를 통하여 트래픽 패턴 및 버스트 어셈블 방식에 따른 슬리핑 시간, 상태 천이 횟수, 패킷 지연시간 및 에너지 절감율을 측정하고 분석한다.

• Journal of Communications and Networks
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• 제18권4호
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• pp.600-609
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• 2016

In this paper, we propose a two-stage base station (BS) sleeping scheme to save energy consumption in cellular networks. The BS sleeping mode is divided into a light sleeping stage and a deep sleeping stage according to whether there is a user in the BS's coverage. In the light sleeping stage, a BS will retain its coverage and frequently switch between the on state and the doze state according to the service characteristics. While in the deep sleeping stage analysis, the BS will shut down its coverage, and neighbor BSs will patch the coverage hole. Several closed-form formulas are derived to demonstrate the power consumption in each sleeping stage and the stage switching conditions are discussed to minimize the average power consumption. The average traffic delay caused by BS sleeping and the average deep sleeping rate under a given traffic load have also been studied. In addition, it is shown that BS sleeping is not always possible because of the limited quality of service (QoS) requirements. Simulation results show that the proposed scheme can effectively reduce the average BS power consumption, at the cost of some extra traffic delay. In summary, our proposed framework provides an essential understanding of the design of future green networks that aim to take full advantage of different stages of BS sleeping to obtain the best energy efficiency.

• 부모자녀건강학회지
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• 제13권2호
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• pp.95-101
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• 2010

Purpose: This study is intended to identify difference postpartum depression according to delivery mode in the postpartum women. Methods: The subjects were 239 postpartum women in D and A city. Data collected from June 9, 2006 to August 6, 2007 using structured questionnaire surveys and convenience sampling. Measuring instrument was BDI (Beck Depression Inventory) translated By Lee and Song (1991). Collected data was analyzed by $x^2$-test, ANCOVA, Stepwise Multiple Regression with SPSS/PC 14.0. Results: There were significant differences in postpartum period ($x^2$=12.40, p = .002) and sleeping hours ($x^2$=9.09, p = .011) as analysed distribution of the subjects according to delivery mode. As result of analyzing the difference of postpartum depression according to delivery mode using ANCOVA, C-sec women's postpartum depression was higher than vaginal delivery women statistically (F=6.32, p = .013). As a result of Multiple Regression, income was a influencing factor of postpartum depression in vaginal delivery women and support of spouse and sleeping hours were influencing factors in C-sec women. Conclusion: There were differences in postpartum depression and their influencing factors according to delivery mode. Therefore it is necessary to develop and study a concrete nursing intervention and strategies for reducing the postpartum depression according to delivery mode.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1925_1926
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• 2009

This paper describes a novel power management circuitry for reducing the sleeping mode power dissipation. Based on the proposed power management circuitry, the sensor module can be activated by RF wake-up signal, perform designated process and deactivate itself. There is absolutely no power dissipation at the sleeping mode which takes almost time of the operation. The temperature sensor module using solar cell as energy source has been fabricated and tested. Experimental results show that the sensor module with 3300 ${\mu}$F for storage capacitor can transmits RF temperature data to a receiver at a distance of 20 m every 15 second in a normal indoor light condition and keep the capacitor voltage over 9 V. And the sensor module can operate 100 times with a single charging, that means it is possible for the sensor module to transmit every 5 minute for 8 hours without light or any other power input during the night time.

• Current Optics and Photonics
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• 제1권4호
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• pp.315-324
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• 2017

In recent years, multicast services such as high-definition television (HDTV), video conferencing, interactive distance learning, and distributed games have increased exponentially, and wavelength-division multiplexing (WDM) networks are considered to be a promising technology due to their support for multicast applications. Multicast survivability in WDM networks has been the focus of extensive attention since a single-link failure in an optical network may result in a massive loss of data. But the improvement of network survivability increases energy consumption due to more resource allocation for protection. In this paper, an energy-efficient multicast algorithm (EEMA) is proposed to reduce energy consumption in WDM networks. Two cost functions are defined based on the link state to determine both working and protection paths for a multicast request in WDM networks. To increase the number of sleeping links, the link cost function of the working path aims to integrate new working path into the links with more working paths. Sleeping links indicate the links in sleep mode, which do not have any working path. To increase bandwidth utilization by sharing spare capacity, the cost function of the protection path is defined to use sleeping fibers for establishing new protection paths. Finally, the performance of the proposed algorithm is evaluated in terms of energy consumption, and also the blocking probability is evaluated under various traffic environments through OPNET. Simulation results show that our algorithm reduces energy consumption while maintaining the quality of service.

• 전자공학회논문지C
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• 제34C권6호
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• pp.37-43
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• 1997

In this paper, an analog-domain powr-reduction technique for a low-voltage CMOS operational amplifier and its application to clock-based VLSI systems are proposed. The proposed technique cuts off the bias current of the op amp during a half cycle of the clock in the sleeping mode and resumes the curent supply sequentially during the remaining cycle of the clock in the normal operating mode. The proposed sequential sbiasing technique reduces about 50% of the op amp power and improves the circuit performance through high phase margin and stable settling behavior of the output voltage. The power-reduction technique is applied to a sample-and-hold amplifier which is one of the critical circuit blocks used in the front-end stage of analog and/or digital integrated systems. The SHA was simulated and analyzed in a 0.8.mu.m n-well double-poly double-metal CMOS technology.

• 한국전자통신학회논문지
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• 제7권5호
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• pp.983-989
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• 2012

IEEE 802.3az LPI 메커니즘은 전송할 데이터가 없을 경우 취침 모드로 천이하여 다수의 컴포넌트들을 저전력 상태를 유지하게 함으로써 에너지 효율성을 향상시킨다. LPI는 소량의 데이터가 주기적으로 전송되는 상황에서는 잦은 전송 모드 변환에 따른 오버헤드 때문에 에너지 효율이 크게 개선되지 못하는 문제점이 있다. 본 논문에서는 전송계층 트래픽 특성 및 네트워크 상태에 따라 LPI 모드 상태 천이를 적응적으로 수행하는 개선된 LPI 메커니즘을 제안한다. 시뮬레이션 방법에 의한 성능 분석을 통해 제안한 메커니즘이 다양한 트래픽 부하에 대해서 기존 방법보다 에너지 효율성을 향상시키는 것으로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.114-130
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• 2021

With the drastic growth of Information and Communication Technology (ICT) industry, global energy consumption is exponentially increased by mobile communications. The huge energy consumption and increased environmental awareness have triggered great interests on the research of dynamic distribution of cell user and traffic, and then designing the energy efficient cellular network. In this paper, we explore the temporal and spatial characteristics of human mobility and traffic distribution using real data set. The analysis results of cell traffic illustrate the tidal effect in temporal and spatial dimensions and obvious periodic characteristics which can be used to design Base Station (BS) dynamic with sleeping or shut-down strategy. At the same time, we designed a new Cell Zooming and BS cooperation mode. Through simulation experiments, we found that running in this mode can save about 35% of energy consumption and guarantee the required quality of service.

• 대한약리학회지
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• 제10권2호
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• pp.13-23
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• 1974

Results of an experiment on the general behavior of rats in order to explore the possible pharmacological actions of Panax Ginseng upon the central nervous system can be summarized as follows: 1) The rats treated with Ginseng-saponin intraperitoneally with the doses of 50 or 100 mg/kg show the decreased sleeping component and increase in lying and grooming component and walking and rearing component of general behavior. 2) There are no difference between control group and saline treated group in pattern of general behavior components. 3) In the Ginseng-saponin treated groups, the amphetamine stimulated walking and rearing component of genenarl behavior are reduced but lying and grooming component are elevated. 4) Ginseng-saponin shows very low acute toxicity in mice. The $LD_{50}$ in mice of 24 hours after intraperitoneal injection was 795 mg/kg. From the above findings, it is to suggest that the Ginseng saponin might stimulate the central nervous system but its mode of action appears to be different from that of amphetamine. And the effects of Ginseng saponin may be varied depending on various experimental situation or condition of animals.

• 한국주거학회:학술대회논문집
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• 한국주거학회 1990년도 학술발표대회논문집
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• pp.15-24
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• 1990

The purpose of this research is to provide the informations on built - in closets and storage in urban apartment houses in korea, considering the mode in living. Since the number of household goods and furniture might be related with the unit size of house(L D K) and district (Seoul. Pusan, Incheon) all data also were evaluated by the struclure of dwelling space and urban area in korea. For being importance of "Anbang" for indoor living, in which Znagnnng, Mungap, a dressing table and hanger are prepared. Preparation of new space in various ways. so many living tools are being used, for example the dinner table with adjustable supporters. A room is specially prepared for storage of season's living goods and furniture. It is very interest that the bed is still net popular, because that is considered as obstruction for the function of "Anbang", specially in small size apartment. Built - in closets and storage In "Anbang" is greatly needed, because most of activities of living involving sleeping are done In that space.