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THE PARTICLE SIZE EFFECT ON COMBUSTION BEHAVIOR OF CELLULOSE INSULATION

  • Choi, Jeong-Hwa;Kim, Hong;Ryu, Kyong-Ok
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.185-192
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    • 1997
  • The combustion of cellulose insulation treated with Borax, Boric acid and Aluminum Sulfate as combustion retardants is examined by candle type combustion tester. The cellulose fibers in cellulose insulation are classified by diameter as less than 0.2mm, 0.2mm-0.5mm, 0.5mm-2mm and more than 2mm. The burning behavior of cellulose insulation are studied by LOI (Limit Oxygen Index: Beginning point of smoldering), L- point (Lower point of combustion transition from smoldering- flaming to flaming combustion), LOI, L-point and H-point rise with the increasing particle size of cellulose fibers because thermal decomposition rate of cellulose fiber decreases. The phenomena of combustion transition from smoldering to flaming combustion are determined by the generating rate of combustible gas and the formation rate of combustible gas mixture within the zone of cellulose fiber heated.

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Effects of Scolopendrid Water-Alcohol Extract Injection Applied to the Acupuncture Point on the Neuropathic Pain in Rats (백서(白鼠)에서 오공약침(蜈蚣藥鍼)이 신경병증성(神經病症性) 통증(痛症)에 미치는 영향(影響))

  • Lee, Sam-Ro;Koo, Sung-Tae;Kim, Sung-Nam;Hwang, Woo-Jun;Lee, Geon-Mok;Cho, Nam-Geun;Lim, Kyu-Sang;Kim, Sung-Chul
    • Korean Journal of Acupuncture
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    • v.21 no.2
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    • pp.47-67
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    • 2004
  • Objectives : In the present study, the effect of Scolopendrid Water-Alcohol Extract (SWAE) applied to acupuncture point BL23 (Shinsu) on the neuropathic pain was examined. A common source of persistent pain in humans is the neuropathic pain. Anti-convulsant drugs are used to treat the neuropathic pain. In the oriental medicine, Scolopendrid was used for long time to treat convulsant syndrome and back pain, etc. Methods : On the bases of the Scolopendrid clinical application, the effect of SWAE applied to the acupuncture point was tested in the rat model of neuropathic pain. Neuropathic pain was induced by tight ligation of L5 spinal nerve. When rats developed pain behaviors, One hundred microliter of SWAE was applied into the ipsilateral BL23 point at a dose of 10 mg/ml under enflurane anesthesia. The foot withdraw latency of the hind limb was measured for an indicator of pain level after each manipulation. Results : SWAE injection increased the mechanical threshold of the foot in the rat model of neuropathic pain significantly for the duration of 4h, suggesting a partial alleviation of pain. SWAE applied to BL23 point produced a significant improvement of mechanical sensitivity of the foot lasting for at least 4h. However, neither contralateral BL23 point, ST25 (Chonchu) point, nor LR3 (Taechung) point produce as much increase of mechanical sensitivity as ipsilateral BL23 point. And, this increase of mechanical sensitivity was dose-dependent. The improvement of mechanical threshold was interpreted as an analgesic effect. In addition, the analgesic effect of Scolopendrid 4 mg/kg injection is equivalent to that of gabapentin 50 mg/kg injection. The relations between SWAE-induced analgesia and endogenous nitric oxide(NO), inducible NO synthase (iNOS)/neuronal NO synthase (nNOS) were also examined. Results were turned out that both NO production and nNOS/iNOS protein expression which are increased by nerve injury were suppressed by SWAE injection applied to BL23 point. Conclusions : The data suggest 1) that SWAE produces a potent analgesic effect on the neuropathic pain model in the rat and 2) that SWAE-induced analgesia modulate endogenous NO through the suppression of nNOS/iNOS protein expression.

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Development of Human Indices to Determine Both Returning Point of Residents and Damage Restoration after the Chemical Accident (화학사고 후 주민복귀 및 피해복구 시점 결정을 위한 인체지표 개발)

  • Yang, JunYong;Heo, JeongMoo;Lee, HyunSeok;Lee, JunSang;Cho, YongSung;Kim, HoHyun;Park, SangHee
    • Journal of Environmental Health Sciences
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    • v.46 no.5
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    • pp.588-598
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    • 2020
  • Objectives: Human indices were developed to determine returning point of residents and damage restoration after the chemical accident Methods: To determine the returning point of residents after the chemical accident, a new concept, the standard man model was introduced as a human index, in which both H-code and its acute effects were main idea. To evaluate the applicability, a hydrogen fluoride leakage accident in Gumi was applied. The returning point were suggested as the conservative remission period of acute effects among relevant hazard effects and compared with actual returning point. The coverage of each age group were considered with reflecting average daily dose expected for actual residents. In addition, a relief-index as a social-scientific approach was reflected as well to apply the damage restoration Results: Actual returning point of residents in Gumi was 88 days; and that of standard man model suggested was 84 days. The expected amount of exposure at aged 12 or under was at least 2.35 times greater than that of this model, 40s, theoretically. However, their population ratio was less than 1%, so 99% of residents could be applied when the standard man model was applied. The relief-index was as an objective and quantitative methodology to apply the qualitative aspect. Conclusions: Although evaluated as a relatively positive result, there was a limitation such as the number of accident applied to the verification of standard man model. The relief index was also considered, but further research should be carried out to find threshold level for the relief.

A Study on the Fire Hazard of Transportation Oil (수송기관용 오일의 화재위험성에 관한 연구)

  • Park, Young Ju;Hwang, Me Jung;Lee, Hae Pyeong;Lee, Seung Chul;Lee, Chang Hyun
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.114-120
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    • 2014
  • The purpose of this study is to conduct the study of the combustion and thermal characteristics through transportation oil for the analysis of fire hazard. Transportation oil breaks down into fuels such as diesel for civilian demands, gasoline, DF1(diesel for military), high sulfur diesel(for marine), kerosene and JP1(for aviation), and lubricants like brake fluid, power steering oil, engine oil, and automatic and manual transmission oil. The experiments of flash point, ignition point, flame duration time, heat release rate were carried out using TAG closed cup flash point tester(AFP761), Cleveland open cup auto flash point analyzer(AFP762), KRS-RG-9000 and Dual cone calorimeter. As a result, the fuel's ignition points were lower than lubricants, especially that of gasoline was not conducted as it has below zero one. Gasoline has the highest ignition point of about $600^{\circ}C$, while the other fuels showed $400{\sim}465^{\circ}C$. For flame duration time, lubricants had over 300 seconds, but fuels had less than 300 seconds except high sulfur diesel(350 seconds). Total heat release rate ranged $287{\sim}462kW/m^2$ for lubricants and gasoline showed the highest total heat release rate, $652kW/m^2$.

Real-Time System Design and Point-to-Point Path Tracking for Real-Time Mobile Robot

  • Wang, F.H.
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.162-167
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    • 2003
  • In this paper, a novel feasible real-time system was researched for a differential driven wheeled autonomous mobile robot so that the mobile robot can move in a smooth, safe and elegant way. Least Square Minimum Path Planning was well used for the system to generate a smooth executable path for the mobile robot, and the point-to-point tracking algorithm was presented as well as its application in arbitrary path tracking. In order to make sure the robot can run elegantly and safely, trapezoidal speed was integrated into the point-to-point path tracking algorithm. The application to guest following for the autonomous mobile robot shows its wide application of the algorithm. The novel design was successfully proved to be feasible by our experiments on our mobile robot Interactive Robot Usher (IRU) in National University of Singapore.

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An Analysis of Textbooks and an Investigation of Science Teacher's Views on 'Boiling Point' and 'Melting Point' (끊는점과 녹는점에 대한 교과서 내용 분석 및 과학교사들의 인식조사)

  • Kim, Seong-Su;Baek, Seong-Hui
    • Journal of the Korean Chemical Society
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    • v.46 no.3
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    • pp.252-264
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    • 2002
  • In this study, the experimental apparatus for boiling point and melting point in science textbooks of various curriculums were analyzed. Science teachers' views on the difference between the experimental value and the value written in textbooks were inquired, too. Their views on the experimental apparatus, nd results of freezing point,melting point, boiling point, fractional distillation, and thermometer calibration were also investigated. The results of this study showed that the types of experimental apparatus for boiling point and melting point were somewhat dif-ferent with science textbooks and curriculum. The teachers' views were also various according to their background. In the experiment of the fractional distillat ion, a large number of teachers recognized mismatch between the exper-imental value and the value written in textbooks as mistake of textbook contents or problem of experiment itself. The teachers of chemistry background take higher recognition of the requirement of thermometer calibration than those of non-chemistry background in middle school.

A Comparative Study on the Anthropometric Method - Anthropometric Point and Line - (인체측정(人體測定) 방법(方法)에 관(關)한 비교(比較) 연구(硏究) - 인체측정(人體測定) 기준점(基準點), 기준선(基準線)을 중심(中心)으로 -)

  • Kwon, Young-Ja;Shim, Boo-Ja
    • Journal of Fashion Business
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    • v.5 no.4
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    • pp.89-100
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    • 2001
  • The major purpose of this study is to show exact and convenient devices and minimize error in body measurement. This study was referred to 13 records and compared 6 items that the investigator's opinion has been differed about anthropometric point and line and suggested convenient and radical device, and measured by if need be. The 30 students from 20 to 25 ages were measured and data was analyzed by mean, std. deviation and paired t-test. The results are as follows. 1. Side neck point has been suggested many devices, but was suggested in this study to decide by M. trapezius, cervicale point and fossa jugularis point. 2. Shoulder point was suggested to decide by point of 1/2 armhole depth, upper arm depth and shoulder depth except acromion point. 3. Waist circumference line has been differed between horizontal line and natural line. The result of measurements was no significant difference between two methods and natural line was convenience. Waist circumference line must considered two methods together for garment construction and somato type. 4. The standard of hip circumference line has been differed between buttock point and trochanterion point. The result of measurements was significant difference between two methods, but two point must considered together because of body type. 5. Chest circumference line at scye has been differed between horizontal line and natural line. The result of measurements was significant difference between two methods and natural line was convenience. Chest circumference line at scye must studied to decide method the line for garment construction.

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A Study on the Point Makeup Purchasing and Using Behavior according to the Personal Color Awareness (퍼스널 컬러 인식에 따른 색조 화장품 구입 및 사용행동)

  • Woo, Soo-Jin;Kim, Yong-Sook
    • The Research Journal of the Costume Culture
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    • v.19 no.5
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    • pp.889-902
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    • 2011
  • The purposes of this study were to identify point makeup purchasing and using behavior according to the personal color awareness. Most women considered their favorite color first when purchasing lipsticks and skin color when purchasing cheek powder or foundation. They considered makeup concept first when applying lipsticks, eye shadows, and cheek powder but skin color applying foundations and manicures. Factors of personal color awareness were preferences & utilization awareness, other's advice, and direct awareness, and were segmented into PC intermediate group, high PC group, and PC retard group. PC intermediate group were in the late 20's and the early 30's, average incomes with high education, and patronized discount stores for point makeups, used fashion color as a criterion when selecting lipsticks, foundations, and manicures, apparel color when applying eye shadows, skin color when applying cheek creams, and preferred imported lipsticks and manicures. High PC group were among unmarried women in the early 20's, university students, high income households with medium level of pocket money, spent more for point makeup, and patronized department stores and internet shopping mall, used skin color or fashion color as criteria when selecting point makeup, referenced makeup concept when applying point makeup, preferred imported point makeup. PC retard group were among married women in the late 30's with low education and low income, spent less for point makeup and pocket money, and selected domestic point makeup, used their favorite color as a criterion when selecting point makeups and apparel color when applying lipsticks and cheek creams.

Comparison of Change-point Estimators in Hazard Rate Models

  • Kim, Jaehee
    • Communications for Statistical Applications and Methods
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    • v.9 no.3
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    • pp.753-763
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    • 2002
  • When there is one change-point in the hazard rate model, a change-point estimator with the partial score process is suggested and compared with the previously developed estimators. The limiting distribution of the partial score process we used is a function of the Brownian bridge. Simulation study gives the comparison of change-point estimators.

Change-Point Estimation and Bootstrap Confidence Regions in Weibull Distribution

  • Jeong, Kwang-Mo
    • Journal of the Korean Statistical Society
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    • v.28 no.3
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    • pp.359-370
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    • 1999
  • We considered a change-point hazard rate model generalizing constant hazard rate model. This type of model is very popular in the sense that the Weibull and exponential distributions formulating survival time data are the special cases of it. Maximum likelihood estimation and the asymptotic properties such as the consistency and its limiting distribution of the change-point estimator were discussed. A parametric bootstrap method for finding confidence intervals of the unknown change-point was also suggested and the proposed method is explained through a practical example.

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