• Title/Summary/Keyword: egress

Search Result 208, Processing Time 0.024 seconds

Adaptive Buffer and Burst Scheme and Its Characteristics for Energy Saving in Core IP Networks (에너지 절약을 위해 적응적 버퍼링 기법을 이용한 버스트 구성 방법 및 특성)

  • Han, Chimoon
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.49 no.10
    • /
    • pp.34-42
    • /
    • 2012
  • This paper analyses the energy saving basic power models in core IP networks, and proposes the adaptive buffer and burst scheme which is a possible energy saving method, and its implementation algorithm in core IP networks. Especially this paper describes the adaptive buffer and burst scheme dynamically varying the buffering interval B according to the input traffic volume of ingress router, and explains the operation principle of proposed scheme. This method is to adjust the buffering interval B according to input traffic volume of ingress router, that is increasing the interval B when input traffic volume is low, and decreasing the interval B when input traffic volume is high between some given interval regions. This method can gets the high energy saving effect as decreasing the transition number of idle/active in networks when input traffic volume is low, and decreasing the transition number of idle/active by the continuous of burst packets in transit router when input traffic volume is high. This paper shows the increasing of asleep rate for the energy saving of core IP networks and confirms the energy saving of core IP networks by the computer simulation. We confirmed that proposed method can be save the energy of IP networks by properly trade off network performances.

Construction of the Smoke Exhaust System and Its Applicability by the Fire Model Test for a Bidirectional Tunnel (대면교행터널에서 배연시스템의 구축과 화재모형실험에 의한 적정성 평가)

  • Lee Sang-Eun;Lee Chang-Woo
    • Tunnel and Underground Space
    • /
    • v.15 no.6 s.59
    • /
    • pp.452-461
    • /
    • 2005
  • In a bidirectional tunnel, the accident rate is 1.5 times as high as that of one directional tunnel , the risk of a fire is increased. On fire, there is a problem that the jet fan should not be operated until completion of refuge. To be special, as the great damages occur owing to the expansion of smoke in long tunnels, there is a need to minimize fatality by constructing cross passage and smoke removal system. This study aims at verifying the efficiency of smoke exhaust system through fire propagation simulation as well as scale model test. The results show that completion of escape through emergency exit requires 335 seconds, while addition of smoke exhaust system reduce the escape time to 185 seconds. Also, near the fire source temperature decreased by about $60^{\circ}C$. Without the exhaust system, fire propagation speed was in the range of 0.36 and 0.82 m/s, and it dropped to $0.27\~0.58\;m/s$ with the exhaust system on. Taking into account the escape speed of tunnel users, usually $0.7\~1.0\;m/s$, the emergency exit built every 150m is sufficient for the safe egress. The ultimate goal of this study is to provide fundamental information for the smoke exhaust system in bidirectional tunnels.

Bovine leukocyte adhesion deficiency

  • Kehrli, Marcus E. Jr.;Park, Yong-ho;Yoo, Han-sang
    • Korean Journal of Veterinary Research
    • /
    • v.39 no.2
    • /
    • pp.247-256
    • /
    • 1999
  • A disease of young Holstein calves characterized by recurrent pneumonia, ulcerative and granulomatous stomatitis, enteritis with bacterial overgrowth, periodontitis, delayed wound healing, persistent neutrophilia and death at an early age had been originally described in 1983 and again in 1987. Most of these calves had stunted growth and a persistent, progressive neutrophilia (often exceeding 100,000/ml). By investigation of pedigrees, all of the affected calves have now been traced to a common sire and confirmed by polymerase chain reaction (PCR) diagnostic DNA testing to be homozygous carriers of a defective allele for bovine CD18. Neutrophils from these calves have several functional deficits and, most importantly, fail to adhere in a ${\beta}_2$-integrin dependent manner. The ${\beta}_2$-integrins represent a family of glycoproteins which participate in various leukocyte adhesion reactions during host defense. The presence or absence of ${\beta}_2$-integrin molecules can be demonstrated on the surface of neutrophils, monocytes and lymphocytes from normal or affected calves using specific monoclonal antibodies and flow cytometry, or by colloidal gold immunolabeling and scanning electron microscopy in backscatter mode. Deficiency of the ${\beta}_2$-integrins on all leukocyte types in Holstein calves is analogous to leukocyte adhesion deficiency (LAD) seen in humans. Neutrophils in bovine (BLAD) and human LAD patients are unable to adhere to the endothelial lining of the cardiovascular system thus interrupting egression of neutrophils into infected tissues. Other leukocytes, while still deficient in expression of the ${\beta}_2$-integrins, are still able to efficiently egress from the blood stream due to interactions of other adhesion molecules that are not as highly expressed on neutrophils. Both BLAD cattle and LAD children (who do not receive bone marrow transplants) often die at an early age as a result of the failure of neutrophils to extravasate into infected tissues. In 1991, Shuster, et $al^{27}$, identified two point mutations within the alleles encoding bovine CD18 in a Holstein calf afflicted with leukocyte adhesion deficiency. One mutation causes an aspartic acid to glycine substitution at amino acid 128 (D128G) in an extracellular region of this adhesion glycoprotein that is highly conserved (> 95% identity) between humans, cattle and mice. The other mutation is silent. Numerous calves with clinical symptoms of leukocyte adhesion deficiency have since been tested and all have been found homozygous for the D128G allele. In addition, calves homozygous far the D128G allele have been identified during widespread DNA testing in the United States. All cattle with the mutant allele are related to one bull, who through artificial insemination (A.I.), sired many calves in the 1950's and 1960's. The carrier frequency of the D128G CD18 allele among U.S. Holstein cattle had reached approximately 15% among active A.I. bulls and 8% among cows. By 1993, the organization of the dairy industry and the diagnostic test developed to genotype cattle, enabled virtually complete eradication of bovine leukocyte adhesion deficiency among current and future A.I. bulls.

  • PDF

A Study on Emergency Evacuation Route Planning and USN-Based Induction Activities of Correctional Facilities (교정시설의 비상시 피난경로계획 및 USN기반 대피유도활동에 관한 연구)

  • Park, Joo-Hyung;Park, Jong-Hyun
    • Fire Science and Engineering
    • /
    • v.25 no.2
    • /
    • pp.39-46
    • /
    • 2011
  • In correctional facilities with majority of occupants in custody, the safe evacuation guide without getaway accidents should be very important due to complexity in escape paths. Fire causes are various in correctional facilities, for example, arson fire is a major cause in mental treatment facilities, however, old facilities or carelessness of flammable materials consist of fire causes in jail facilities. Both types of correctional facilities are the same in terms of many casualties from the fire cases. The thesis focus on escape paths and evacuation guide plans on the basis of analysis on fire cases and structural vulnerability, and then an electronic unlocking system is concededly installed for safe evacuation of occupants in custody without getaway accidents. Especially, the effect of the electronic unlocking system is going to be analyzed on the basis of RSET (required safe egress time) in order to realize for the occupants to evacuate safely to the front yard in case of emergency. In conclusion, if electronic security allowed system with USN (Ubiquitous Sensor Networks) technology should be installed in multi-storey correctional buildings, it is proposed that the occupants in custody might be a guided safely without getaway trials.

A Study on Smoke Extract Vents in a Subway with Screen door by Evacuation Performance Evaluation through RSET vs. ASET based on Computer Simulations (스크린도어가 설치된 지하철 승강장의 대피안전성 평가를 통한 제연환기구의 방재성능 개선방안 연구)

  • Park, Hyung-Joo;Lee, Young-Jae;Shin, Dong-Cheol;Baek, Dong-Ho
    • Journal of the Korean Society for Railway
    • /
    • v.10 no.5
    • /
    • pp.511-519
    • /
    • 2007
  • This study provides comprehensive design improvements covering technical issues concerning life safety matter In case of fire train stoppage in the middle of a tunnel. Recently Government announced that most of subway platforms will have screen doors in 3 years. Therefore, many fire safety engineers considered that they may contribute on life safety on train stoppage in tunnel. Especially The screen door can protect platform from smoke along tunnel ceiling when fire train stopped in tunnel. The study showed that platform ventilation ducts and the a tunnel ventilation chimney in the middle of tunnel in exiting subway tunnel could not guarantee life safety ability in terms of RSET vs. ASET comparison. Furthermore during evacuation process many peoples may be threatened from the smoke spread from the origin of fire. Although only additional vertical route can be installed in tunnels In order to decrease RSET, it will costs high or no spaces remains in outside on the road. The study suggested that increase of ASET can be best solution without additional escape route, therefore alternative design methods suggested on the base of simulation results. Finally the study shows alternative methods can give good result in terms of evacuation performance evaluation. The evacuation performance evaluation helps the decision-maker to determine the preferred alternatives or upgrades to existing tunnel infrastructure and other measure to meet safety objectives. Finally, the study details the effectiveness of measures the can be taken to reduce the risk of incidents in subway tunnels.

Analysis of the Evacuation Safety with the Structure and Opening/Closing of Exits in a Fire at a Highway Service Area (고속도로 휴게소 화재 시 출입문의 구조와 개폐에 따른 피난안전성 분석)

  • Lee, Jai Young;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
    • /
    • v.7 no.2
    • /
    • pp.419-425
    • /
    • 2021
  • This study analyzed the safety of evacuation according to the number of exits and the direction of evacuation routes with evacuation simulations of the Pathfinder in case of a fire at a highway service area. It was also analyzed of the difference in RSET by comparing the single or double types of the exit of a facility. The results were as follows. When only one direction exit was opened, all of the RSET were exceeded. When two or more different directions were opened according to the general principle of evacuation, all results met the RSET. The simulations showed that two or more different directions were more shortened in RSET than the one same direction. The result of the types of doors showed that the single type door was shortened in RSET rather than the double type doors. For the evacuation safety in a fire at the highway service areas, firstly, it is necessary to secure two or more exits in a fire at all times. Secondly, the exits should not be same directions. Finally, it is suggested that the exit should be installed with a single type of door.

Reviewing the Expandability of KBimCode based on the Comparison between Korean and Chinese Building Act - Centered around the Egress and Fire Safety Related Regulations - (한.중 건축법규 비교분석을 통한 KBimCode의 확대 적용가능성 고찰 - 피난 및 방화와 관련된 법규항목을 중심으로 -)

  • Huang, JinHua;Park, SeoKyung;Lee, Jin-Kook
    • Design Convergence Study
    • /
    • v.15 no.6
    • /
    • pp.73-92
    • /
    • 2016
  • As one of empirical research and developments on BIM applications to improve design quality and productivity of building, efforts have been devoted to automated compliance checking of building design for building permit. KBimLogic is a mechanism that translate Korean Buidling Act to the computational language called KBimCode. KBimCode aims to standardized and neutral language that can be applied to various design rules. This paper focuses on testing expandability of KBimCode by appling it on Chinese Building Act. We analyzed Chinese national regulation on fire protection and evacuation, based on 1) Object·property, 2) function for predicate processing, 3) relationship of sentences. As a result, Chinese Building Act were successfully translated to KBimCode with some important implications for further application. Based on the finding of the paper, KBimCode is expected to be applicable to kinds of design rules.

Implementation of IoT-Based Irrigation Valve for Rice Cultivation (벼 재배용 사물인터넷 기반 물꼬 구현)

  • Byeonghan Lee;Deok-Gyeong Seong;Young Min Jin;Yeon-Hyeon Hwang;Young-Gwang Kim
    • Journal of Internet of Things and Convergence
    • /
    • v.9 no.6
    • /
    • pp.93-98
    • /
    • 2023
  • In paddy rice farming, water management is a critical task. To suppress weed emergence during the early stages of growth, fields are deeply flooded, and after transplantation, the water level is reduced to promote rooting and stimulate stem generation. Later, water is drained to prevent the production of sterile tillers. The adequacy of water supply is influenced by various factors such as field location, irrigation channels, soil conditions, and weather, requiring farmers to frequently check water levels and control the ingress and egress of water. This effort increases if the fields are scattered in remote locations. Automated irrigation systems have been considered to reduce labor and improve productivity. However, the net income from rice production in 2022 was about KRW 320,000/10a on average, making it financially unfeasible to implement high-cost devices or construct new infrastructure. This study focused on developing an IoT-Based irrigation valve that can be easily integrated into existing agricultural infrastructure without additional construction. The research was carried out in three main areas: Firstly, an irrigation valve was designed for quick and easy installation on existing agricultural pipes. Secondly, a power circuit was developed to connect a low-power Cat M1 communication modem with an Arduino Nano board for remote operation. Thirdly, a cloud-based platform was used to set up a server and database environment and create a web interface that users can easily access.