• Title/Summary/Keyword: 802.15.6

Search Result 223, Processing Time 0.031 seconds

The photo-removal characteristic of VOCs by photocatalyst/scoria/loess concrete (광촉매가 첨가된 스코리아/황토/콘크리트의 VOCs 제거특성)

  • Ko, Seong-Hyun;Lee, Jae-Hoon;Hong, Chong-Hyun;Ryu, Seong-Phil;Kim, Moon-Hoon;Moon, Kyung-Jong
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2006.05b
    • /
    • pp.585-588
    • /
    • 2006
  • The environment-friendly building material, photocatalyst/scoria/loess concrete, was prepared using scoria and loess (which have merits as building materials) and photocatalyst (which has the functions to compose the environmental contaminants and of self cleaning). In order to apply this material as a building material, the compressive and flexible strengths, and water absorptivity (which have been set by Korea Industrial Standard) were measured. The optimum mixing ratio of photocatalyst/scoria/loess concrete was obtained at the condition of $393kg/m^3$ of coarse aggregate, $802kg/m^3$ of fine aggregate in case of scoria, $80kg/m^3$ of loess, $12kg/m^3$ of photocatalyst, $400kg/m^3$ of cement, and $2kg/m^3$ of AE water reducing agent. The photocatalyst/scoria/loess concrete prepared by above mixing ratio of raw materials showed 25 MPa of compressive strength, $3.8{\sim}4.6$ MPa of flexible strength and $11.4{\sim}12.0%$ of water absorptivity, indicating that the quality of this material was suitable for Korea Industrial Standard (more than 21 MPa for compressive strength, more than 2.0 MPa for flexible strength in case of lightweight aggregate, and less than 15 % for water absorptivity in case of clay brick) for using as a building material.

  • PDF

Novel Architecture for Efficient Implementation of Dimmable VPPM in VLC Lightings

  • Jeong, Jin-Doo;Lim, Sang-Kyu;Jang, Il-Soon;Kim, Myung-Soon;Kang, Tae-Gyu;Chong, Jong-Wha
    • ETRI Journal
    • /
    • v.36 no.6
    • /
    • pp.905-912
    • /
    • 2014
  • In this paper, a new architecture is proposed to achieve complexity efficiency in implementing variable pulse position modulation (VPPM). VPPM, specified in IEEE 802.15.7, can support wireless communication and dimming control simultaneously using visible light. The proposed architecture is based on the VPPM signal property in which the transition point of the modulated output is obtained by counting the sample index and comparing it to both the assigned dimming factor and the transmitting data. Therefore, the proposed architecture can be composed of simple logics, including a counter, a comparator, and an inverter, all of which are insensitive to the dimming resolution in contrast to a conventional codeword-table method. This paper describes the verification of the proposed algorithm through a register-transfer level implementation of the codeword and proposed architectures. In comparison with the codeword-table method, the proposed method gains a nine-fold complexity reduction at a 1% dimming-step resolution.

A Study on Toponymical Characteristics of Station Names of Seoul Metropolitan Railway System (수도권 전철 역명의 지명학적 특성에 관한 연구)

  • Song, Ho-Yul
    • Journal of the Korean association of regional geographers
    • /
    • v.15 no.6
    • /
    • pp.789-802
    • /
    • 2009
  • The purpose of this study is to reveal general features and toponymical characteristics of station names of Seoul metropolitan railway system. Principal results of this study are as follows. At the present time of December, 2009, the number of station which is run is 508, the number of transfer station is 61 and the number of station which has another name is 89. Two-letter station names are 61.99%, and three-letter station names are 20.59%. Geographical names used as station name are classified into three types : administrative, physical, and human placename. In the three types, administrative placename is the most and physical placename is the least. In the administrative placename, the name of 'Dong' is the most. In the physical placename, the name of mountain is the most. In the human placename, the name of facilities is the most.

  • PDF

mSFP: Multicasting-based Inter-Domain Mobility Management Scheme in Sensor-based Fast Proxy Mobile IPv6 Networks (센서기반 FPMIPv6 네트워크에서 멀티캐스팅 기반의 도메인간 이동성관리 기법)

  • Jang, Hana;Jeong, Jongpil
    • KIPS Transactions on Computer and Communication Systems
    • /
    • v.2 no.1
    • /
    • pp.15-26
    • /
    • 2013
  • IP-based Wireless Sensor Networks (IP-WSNs) are gaining importance for their broad range of applications in health-care, home automation, environmental monitoring, industrial control, vehicle telematics and agricultural monitoring. In all these applications, mobility in the sensor network with special attention to energy efficiency is a major issue to be addressed. Because of the energy inefficiency of networks-based mobility management protocols can be supported in IP-WSN. In this paper we propose a network based mobility supported IP-WSN protocol called Multicasting-based inter-Domain Mobility Management Scheme in Sensor-based Fast Proxy Mobile IPv6 Networks (mSFP). Based on [8,20], We present its network architecture and evaluate its performance by considering the signaling and mobility cost. Our analysis shows that the proposed scheme reduces the signaling cost, total cost, and mobility cost. With respect to the number of IP-WSN nodes, the proposed scheme reduces the signaling cost by 7% and the total cost by 3%. With respect to the number of hops, the proposed scheme reduces the signaling cost by 6.9%, the total cost by 2.5%, and the mobility cost by 1.5%. With respect to the number of IP-WSN nodes, the proposed scheme reduces the mobility cost by 1.6%.

Effects of Phase Feeding on Growth Performance, Nutrient Digestibility, Nutrient Excretion and Carcass Characteristics of Finishing Barrow and Gilt

  • Kim, Y.G.;Jin, J.;Kim, J.D.;Shin, I.S.;Han, In K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.13 no.6
    • /
    • pp.802-810
    • /
    • 2000
  • A total of 120 finishing crossbred pigs ($Landrace{\times}Large$ $White{\times}Duroc$) with equal numbers of barrows and gilts weighing 58.5 kg body weight were used in a feeding trial, and 6 pigs (three of each sex) were used in a metabolic trial to investigate the effect of phase feeding. Finishing period was divided into two phases and 4 different diets were fed for those periods. Growth performance was not significantly different among treatments within the same sex. This result showed that 16% crude protein for early finishing period and 14% crude protein diet for late finishing period should be optimum. During the early finishing period, only feed intake was significantly different between sexes (p<0.01), but in late finishing period daily weight gain (p<0.001) and feed intake (p<0.01) of barrows were significantly higher than those of gilts. During the early finishing period, digestibilities of dry matter, protein and phosphorus were significantly higher in gilts than in barrows (p<0.05). However, there was no treatment effect within same sex during the early and late finishing period. During early finishing period, excretion of N of pigs fed 16% CP diet in early and 14% CP diet in late-finishing period was less than that of pigs fed 17% CP diet in early and 15% CP diet in late-finishing period (p<0.05), but the difference was not significant. During the late finishing period, N excretion with two phase feeding was reduced by 8.5% compared with single feeding. In gilts, total cost reduction by two phase feeding compared to single feeding was 9.1%, but in barrows it was just 3.19%. Relative margin increased with two phase feeding by 2.5% in gUts and 0.2% in barrows. There was a tendency that backfat thickness at 10th rib of gilts was thinner than that of barrows (p>0.05). Within the same sexes, there was no treatment effect on back fat thickness (p>0.05). Carcass grade was improved by two phase feeding compared to single feeding. Carcass grade of gilts was significantly better than that of barrows (p<0.001). From this results, it is concluded that finishing pigs could be fed two-phase diets to improve profit and reduce pollution.

Optimization of the Conditions of Flavonoid Extraction From Tartary Buckwheat Sprout Using Response Surface Methodology (반응표면분석법을 이용한 타타리메밀싹에서 플라보노이드 추출 최적화)

  • Shin, Jiyoung;Choi, Iseul;Hwang, Jinwoo;Yang, Junho;Lee, Yoonhyeong;Kim, So-i;Cha, Eunji;Yang, Ji-Young
    • Journal of Life Science
    • /
    • v.30 no.12
    • /
    • pp.1101-1108
    • /
    • 2020
  • Tartary buckwheat is a grain with many flavonoids, such as rutin, quercetin, kaempferol, and myricetin. This study aimed to optimize extraction conditions to maximize the rutin, quercetin, and myricetin contents of tartary buckwheat sprout extracts using response surface methodology. A BoxBehnken design containing 15 experiments was employed to evaluate the effects of extraction conditions, such as temperature (X1, 50~70℃), extraction time (X2, 5~9 hr), and ethanol concentration (X3, 60~90%). The coefficients of determination (R2) for all the dependent variables (extraction temperature, extraction time, and extraction ethanol concentration) were determined to be over 0.95, indicating significance. The p-value of the model in lack of fit was over 0.1 than means, indicating that the model was well predicted. The optimal extraction conditions for rutin, quercetin, and myricetin contents were obtained at X1 = 51.03, X2 = 6.62, and X3 = 69.16, respectively. Under these optimal conditions, the predicted rutin, quercetin, and myricetin contents were 808.467 ㎍/ml, 193.296 ㎍/ml, and 37.360 ㎍/ml, respectively. For the validation of the model, ten experiments were performed and the experimental rutin and quercetin contents were measured at 802.84±8.49 ㎍/ml, 193.76±2.80 ㎍/ml, and 34.84±0.43 ㎍/ml, respectively. The experimental rutin and quercetin contents were similar to the predicted contents, but the experimental myricetin content was lower than predicted.

Analysis and Research of 119 Silver Ambulance Activities and Its Development Methods (일부지역 119 노인전용구급차(Silver Ambulance)의 활동분석 및 발전방안)

  • Kwon, Hay-Rran
    • The Korean Journal of Emergency Medical Services
    • /
    • v.11 no.3
    • /
    • pp.191-204
    • /
    • 2007
  • This study analyzes use and operation of silver ambulance with 110 patients who had used silver ambulance in Gwangju and Jeonnam regions from June of 2006 to June of 2007 and 53 paramedics who are involved directly in ambulance operation and the results of this analysis are as follows. 1. Users' health conditions, 69.1% of users answered as bad and 67.3% suffered from chronic diseases over 3 months and it was found that they used silver ambulance due to their bad health conditions. 2. Cronbach's alpha was 0.630 and family function index was generally reliable and solution was high as 1.60, but total points were low as 7.11 and it was considered that they had family troubles. 3. On the question of ambulance use, 44.5% answered they used it because it is free, 53.6% used it for appointed medical examination and treatment and 18.1% used it for emergency. 4. Degrees of satisfaction with ambulance and paramedics were 95.4% and 76.4% respectively and 80.0% of ambulance users answered ambulance arrived quickly within 15 min. 5. Correlation($x^2 $) between family or relative's residence and frequency of visits was 86.367 and its significance probability was 0.00 and it was found that it was significant in the level of 0.1%, but correlation($x^2 $) between visitors other than family or relatives and frequency of visits was 14.768 and its significance probability was 0.25 and it was found that it was not significant in the level of 5%. 6. Correlation($x^2 $) between transfer operation speed and mobilization time was found that it was not significant in the level of 5%. Correlation($x^2 $) between their own health condition purpose of ambulance use was 13.802 an 5.696 and its significance probability was 0.93 and it was found that it was not significant in the level of 1%, and it was considered because paramedics carried patients with safe operation.

  • PDF

CRP-CMAC: A Priority-Differentiated Cooperative MAC Protocol with Contention Resolution for Multihop Wireless Networks

  • Li, Yayan;Liu, Kai;Liu, Feng
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.7 no.11
    • /
    • pp.2636-2656
    • /
    • 2013
  • To improve the cooperative efficiency of node cooperation and multiple access performance for multihop wireless networks, a priority-differentiated cooperative medium access control protocol with contention resolution (CRP-CMAC) is proposed. In the protocol, the helper selection process is divided into the priority differentiation phase and the contention resolution phase for the helpers with the same priority. A higher priority helper can choose an earlier minislot in the priority differentiation phase to send a busy tone. As a result, the protocol promptly selects all the highest priority helpers. The contention resolution phase of the same priority helpers consists of k round contention resolution procedures. The helpers that had sent the first busy tone and are now sending the longest busy tone can continue to the next round, and then the other helpers that sense the busy tone withdraw from the contention. Therefore, it can select the unique best helper from the highest priority helpers with high probability. A packet piggyback mechanism is also adopted to make the high data rate helper with packet to send transmit its data packets to its recipient without reservation. It can significantly decrease the reservation overhead and effectively improve the cooperation efficiency and channel utilization. Simulation results show that the maximum throughput of CRP-CMAC is 74%, 36.1% and 15% higher than those of the 802.11 DCF, CoopMACA and 2rcMAC protocols in a wireless local area network (WLAN) environment, and 82.6%, 37.6% and 46.3% higher in an ad hoc network environment, respectively.

Lightweight IPsec protocol for IoT communication environments (IoT 통신 환경을 위한 경량 IPsec 프로토콜 연구)

  • Song, In-A;Oh, Jeong-Hyeon;Lee, Doo-Won;Lee, Young-Seok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.11 no.1
    • /
    • pp.121-128
    • /
    • 2018
  • Internet of Things architecture connected to the Internet is a technology. However, Many paper research for the lightweight Protocol of IoT Environment. In these Paper excluded secure problem about protocol. So Light weight Protocol has weakness of secure in IoT environment. All of IoT devices need encryption algorithm and authentication message code for certain level of security. However, IoT environment is difficult to using existing security technology. For this reason, Studies for Lightweight IPsec is essential in IoT environment. For Study of Lightweight IPsec, We analyze existing protocols such as IPsec, 6LoWPAN for IEEE 802.15.4 layer and Lightweight IPsec based 6LoWPAN. The result is to be obtained for the lightweight IPsec protocols for IoT environment. This protocol can compatible with Internet network.

Performance Analysis and Evaluation of Hybrid Compensation Algorithm for Localization (하이브리드형 위치인식 보정 알고리즘 성능 분석 및 평가)

  • Kwon, Seong-Ki;Lee, Dong-Myung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.6
    • /
    • pp.2263-2268
    • /
    • 2010
  • In this paper, the hybrid compensation algorithm($A_{HB}$) for localization using the Compensation Algorithm distance($CA_d$) and the Algorithm of Equivalent Distance Rate(AEDR) in SDS-TWR(Symmetric Double-Sided Two-Way Ranging) is suggested and the performance of the proposed algorithm is analyzed by practical experimentations. From experimentations, it is confirmed that the errors are reduced in 28 coordinates of total 32 coordinates in the experimental region and the errors are reduced about above 70% in the assigned 3 type error level ranges by $A_{HB}$. Also, it is analyzed that the average localization error is reduced from 2.67m to 1.19m as 55.4% in total 32 coordinates by $A_{HB}$ and the error compensation capability of $A_{HB}$ is very excellent as above 90%. From above results, we have seen that the error reduction ratio and error compensation capability of $A_{HB}$ is more excellent than each $CA_d$ or AEDR.