• Title/Summary/Keyword: Limits

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Economic Design of $\bar{X}$-Control Charts with Warning Limits under Weibull Failure Model (와이블 고장모형 하에서 경고한계를 고려한 $\bar{X}$ 관리도의 경제적 설계)

  • Jeong, Dong-Wook;Lee, Joo-Ho
    • Journal of Korean Society for Quality Management
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    • v.40 no.2
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    • pp.186-198
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    • 2012
  • Since Duncan(1956) first proposed an economic design of $\bar{X}$-control charts, most of the succeeding works on economic design of control charts assumed the exponential failure model like Duncan. Hu(1984), however, assumed a more versatile Weibull failure model to develop an economic design of $\bar{X}$-control charts and Banerjee and Rahim(1988) further improved Hu's design by changing the assumption of fixed-length sampling intervals to variable-length ones. In this article we follow the approach of Banerjee and Rahim(1988) but include a pair of warning limits inside the control limits in order to search for a failure without stopping the process when the sample mean falls between warning and control limits. The computational results indicate that the proposed model gives a lower cost than Banerjee and Rahim's model unless the early failure probability of a Weibull distribution is relatively large. The reduction in cost is shown to become larger as the cost of production loss outweighs the cost of searches for a failure.

Structural Properties of Steel-glulam Composite Column

  • Jang, Sang-Sik;Kim, Yun-Hui;Shin, Il-Joong
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.5
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    • pp.399-404
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    • 2010
  • A new green home designed to save money while at the same time saving the environment with some of the finest green features available in the market. Composite column composed of structural steel and structural glued laminated timber is avery Eco-friendly building products for design building because that use recycled or second hand. For compare to compressive strength of structural glued laminated timber (glulam), structural steel, and composite column (steel-glulam), tested compressive strength of each specimen. 1) structural glued laminated timber : Theoretical compressive strength is 151.6 kN similar to elastic limits. 2) structural steel (H type) : Theoretical compressive strength is 148.2 kN little under the elastic limits. 3) structural steel (D type) : Theoretical compressive strength is 147.3 kN upper than the elastic limits. 4) composite column : Actual elastic limits are about 600 kN. Result in, composite column improve compressive strength of Structural steel column and provide structural stability of the building.

Comparison with decompression time and modes of air decompression tables in 5 countries (5개국 공기잠수감압표의 감압시간과 감압방법 비교)

  • Kang, Joonhyuk
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.26 no.4
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    • pp.445-453
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    • 2016
  • Objectives: The objective of this study is to assess relative safety level of the decompression tables in Ministry of Employment and Labor Public Notice No. 2014-28 in comparison with overseas decompression tables. Methods: Decompression tables in the Public Notice No. 2014-28 were compared with examples from Japan, the USA, Canada, and France in terms of ascent rate, surface intervals after exceptional exposures, oxygen decompression and allowable partial pressure, depth limits in air diving, no-decompression limits, and decompression time and methods. Results: Public Notice No. 2014-28 does not include air diving depth limits, exceptional exposure limits, mandatory surface intervals after exceptional exposures, oxygen decompression, and surface decompression schedules. Its decompression time was found to be the shortest among the five decompression tables. Conclusions: Public Notice No. 2014-28 has the lowest safety level in comparison with overseas decompression tables. Deck decompression chambers are not applicable due to no regulations on surface interval and oxygen use in the chamber for decompression.

Experiences of Participation in Dementia Prevention Program for Older Adults in Nursing Homes (요양시설노인의 치매예방 프로그램 참여 경험)

  • Lim, Sun Ok;Jo, Hyun Mi
    • The Korean Journal of Rehabilitation Nursing
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    • v.19 no.2
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    • pp.128-137
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    • 2016
  • Purpose: This study was designed to describe the experiences of dementia prevention program for older adults in nursing homes. Methods: Four focus group interviews (FGI) after the program were conducted with 35 participants. All interviews were audio-taped and transcribed verbatim. The transcribed data were analyzed by Colaizzi's phenomenological method. Results: Four themes emerged as a result of analysis. Participants without dementia reported "I don't have dementia yet." This statement probably reflects ignoring potential dementia. Motivation for participating the dementia prevention program were to reduce boredom, to enjoy exercising and communicating with others, and to follow group activities. Participants reported the positive effects of the program; (a) benefits from the repeating learned activities; (b) improvements of memory and emotional stability. A few participants reported their inability to follow the program due to physical and environmental limits. However, other participants reported their efforts to overcome physical limits and perform the activities regardless their limits. People who performed the activities with physical limits reported that their self-satisfaction was increased. Conclusion: Results of this study showed that participants without dementia were able to actively participate in dementia prevention programs and showed memory, emotional and behavioral improvements. Therefore, these findings can be used for developing customized dementia prevention programs in nursing homes.

Determination of Derived Release Limits for a CANDU Nuclear Power Plant (CANDU형 원전에서의 유도방출한도 결정)

  • Kim, Kyo-Youn;Hwang, Hae-Ryong;Kim, Jong-Kyung
    • Journal of Radiation Protection and Research
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    • v.19 no.1
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    • pp.23-35
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    • 1994
  • A computer code DRL was developed to calculate the derived release limits at CANDU type nuclear power plants. The derived release limits resulting from DRL code is to set guidelines for the release of radionuclides in airborne and water-borne effuents during normal operations of a CANDU type nuclear power plant. The DRL code generally follows the methodology Prescribed in the CSA standard N288.1-M87 and uses the Parameter values recommended in the same standards. The DRL code was used to calculate a set of preliminary derived release limits for the Wolsong NPP.

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A Study of Forming limits of Transformation mode of AZ31 Alloy sheet (AZ31 합금 판재의 변형모드에 따른 성형한계에 관한 연구)

  • Jung, J.H.;Lee, Y.S.;Kwon, Y.N.;Lee, J.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.378-382
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    • 2008
  • Since the sheet metal forming of Mg alloy is perform at elevated temperature, the effect of strain rates related with the forming temperature and forming speed and R-value is very important factor for formability and forming limits and deep drawing. It is investigated that the effect of material properties such as various temperature, forming speed and strain rates on formability and R-value of Mg alloy sheet in round cup deep drawing. Therefore, the investigation for process variables is necessary to improve formability and forming limits and deep drawing. Also, the effects of strain rate and drawbility were studied by the experiment. The temperature, forming speed, and strain rates and R-value are investigated. Forming of Mg alloy takes consider into temperature, proper forming speed and strain-rate and R-value the formed parts were good without defects for forming limits and deep drawing.

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Prediction of Upper Explosion Limits (UEL) of Acids and Ketones by Using Setaflash Tester (Setaflash 장치를 이용한 산류와 케톤류의 폭발상한계 예측)

  • Ha, Dong-Myeong
    • Fire Science and Engineering
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    • v.25 no.2
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    • pp.114-119
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    • 2011
  • Explosion limit and flash point are the major combustion properties used to determine the fire and explosion hazards of the flammable substances. In this study, in order to predict upper explosion limits (UEL) for acids and ketones, the upper flash point of these were measured under the VLE (vaporliquid equilibrium) state by using Setaflash closed cup tester (ASTM D3278). The UELs calculated by Antoine equation by using the experimental upper flash point are usually lower than the several reported UELs. From the given results, using the proposed experimental and predicted method, it is possible to research the upper explosion limits of the other flammable substances.

Measurement reliability of irreversible stress/strain limits in Sn-Cu double layer stabilized IBAD/RCE-DR processed GdBCO coated conductor tapes under uniaxial tension at 77 K

  • Bautista, Zhierwinjay;Diaz, Mark Angelo;Shin, Hyung-Seop;Lee, Jae-Hun
    • Progress in Superconductivity and Cryogenics
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    • v.20 no.4
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    • pp.36-40
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    • 2018
  • In this study, the electromechanical properties in Sn-Cu double layer stabilized GdBCO coated conductor (CC) tapes with and without external lamination under uniaxial tension were examined at 77 K and self-field. Their irreversible stress and strain limits were determined using a loading-unloading scheme based on different critical current ($I_c$) recovery criteria. The repeated tests were performed and statistical estimation was done to check the reproducibility depending on the criterion adopted in evaluating the electromechanical properties. From the results, it showed that the Sn-Cu double-layer stabilized CC tapes have the higher irreversible stress limit, but lower irreversible strain limit as compared to brass laminated ones. Through the repeated tests, it can be found that a small scattering of irreversible limits existed in both CC tape samples. Finally, similar strain sensitivity of $I_c$ in both CC tapes was obtained.

Limits of Multicultural Imagination and the Anti-Refugee Controversy in Contemporary China

  • Wang, Jing
    • Journal of Contemporary Eastern Asia
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    • v.19 no.2
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    • pp.125-147
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    • 2020
  • On the World Refugee Day in 2017, Yao Chen, a Chinese actress, philanthropist, and social media influencer, posted messages in her Weibo in support of the United Nations Refugee Agency (UNHCR). Yet, social media users quickly interpreted this supportive message of the refugee program as encouraging people to "accept and receive refugees" (jieshou nanmin) into China. Particularly, the category of Middle Eastern refugees elicited most criticism in China's cyberspace. As the inclusion of refugees is an integral part of immigrant multiculturalism, this article examines the limits of multicultural imagination of refugees―particularly those from the Middle Eastern and North Africa―in contemporary China. I argue that the limits of multicultural imagination in contemporary China is profoundly shaped by an intricate interweaving of domestic policies and global imaginaries toward refugees. By deploying a mixed methodology, such limits are examined from legal-institutional, ideological, and sociocultural perspectives. More specifically, three interrelated aspects will be highlighted in the article: (1) the global circulation of right-wing populism imaginaries, and their entanglements with the anti-Muslim sentiments in contemporary China; (2) the current insufficiency of the legal-institutional framework regarding refugees and asylum-seekers, which needs to be contextualized in China's modern history of dealing with refugee issues; (3) population politics, the rise of Han-centric nationalism, and their constraining impact on the interpretation of historical events related to cultural diversity. In conclusion, this article also offers potential implications for further examining the different yet potentially intersected genealogies of multicultural imaginaries beyond the Middle Eastern and North African refugees in Asia.

Fix-to-Fix Navigation Complement Using Limits of Trigonometric Functions (삼각함수의 극한을 활용한 Fix-to-Fix 항법 보완)

  • Bum-su Kim
    • Journal of Advanced Navigation Technology
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    • v.27 no.3
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    • pp.274-280
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    • 2023
  • The Fix-to-Fix Navigation is the technique for aircraft pilots to find out estimated Heading when crossing from present fix to other fix to want to go in the air. Because this is based on the Rule of Thumb method from one's experience, it could not find out exact estimated Heading. Furthermore if the pilot nears going fix, Bearing Pointer and Course Indicator of HSI are too close to use this technique, that makes the pilot lost in the air. In this paper, We take Limits of Trigonometric Functions into the Fix-to-Fix Navigation to overcome these disadvantages. This study introduces two solutions using Limits of Trigonometric Functions when doing Fix-to-Fix Navigation and analyzes the error of this solutions.