• International Journal of Quality Innovation
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• 제3권2호
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• pp.74-83
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• 2002

Process capability indices as an important kind of indices are intended to provide single-number assessments of the inherent process capability to meet specification limits on quality characteristic(5) of interest. In this paper the condition for the application of process capability indices is analyzed. On the basis of process capability indices, dynamic process capability indices as a new kind of indices to show the current process capability are discussed and the condition for the application of dynamic process capability indices is exhibited. Comparison between process capability index and dynamic process capability index and comparison between $D_p$ and $D_pk$ are made and the conclusions provide the approach for process control. According to the requirement of process capability indices provided by customer, quality control based on process capability indices dynamic process capability indices is discussed.

• 산업경영시스템학회지
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• 제26권3호
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• pp.39-49
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• 2003

Statistical process cintrol is intended to assist operators of a stable system in monitoring whether a change has occurred in the process, and it uses several control charts as main tools. In design and use of control chart, it is rational that probability of false alarm is minimized in stable process and probability of detecting shifts is maximized in out-of-control. In this study, we establish bootstrap control limits for robust M-estimator chart by applying the bootstrap method, called resampling, which could not demand assumptions about pre-distribution when the process is skewed and/or the normality assumption is doubt. The results obtained in this study are summarized as follows : bootstrap M-estimator control chart is developed for applying bootstrap method to M-estimator chart, which is more robust to keep ARL when process contain contaminate quality characteristic.

• 국제초고층학회논문집
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• 제10권1호
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• pp.63-71
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• 2021

Since 2006, the number of completed high-rise buildings over 200 meters have increased rapidly. Although there were some short-term cyclical troughs, the overall trend has still been growing. No longer constrained by technological limits, the development of high-rise buildings now depends on cooperation and compromise between social, economic, and political factors. This article extracts statistical data from the Council on Tall Buildings and Urban Habitat (CTBUH) to focus on the completion of high-rise buildings of 200 meters and above over the past 20 years from 2000 to 2019. Similarities and differences in the number, distribution, and function of high-rise buildings are analyzed, The paper also compares the impact of different political and economic environments on the development trends of high-rise buildings in China, the United States and the UAE.

• 대한수학회논문집
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• 제38권3호
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• pp.787-805
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• 2023

Let (Ω, µ) be a measure space and {τ_α}_α∈Ω be a normalized continuous Bessel family for a finite dimensional Hilbert space 𝓗 of dimension d. If the diagonal ∆ := {(α, α) : α ∈ Ω} is measurable in the measure space Ω × Ω, then we show that $$\sup\limits_{{\alpha},{\beta}{\in}{\Omega},{\alpha}{\neq}{\beta}}\,{\mid}{\langle}{\tau}_{\alpha},\,{\tau}_{\beta}{\rangle}{\mid}^{2m}\,{\geq}\,{\frac{1}{({\mu}{\times}{\mu})(({\Omega}{\times}{\Omega}{\backslash}{\Delta})}\;\[\frac{{\mu}({\Omega})^2}{\({d+m-1 \atop m}\)}-({\mu}{\times}{\mu})({\Delta})\],\;{\forall}m{\in}{\mathbb{N}}.$$ This improves 48 years old celebrated result of Welch [41]. We introduce the notions of continuous cross correlation and frame potential of Bessel family and give applications of continuous Welch bounds to these concepts. We also introduce the notion of continuous Grassmannian frames.

• 한국전문물리치료학회지
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• 제7권2호
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• pp.1-19
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• 2000

Decreased equilibrium in standing and walking is a common problem associated with hemiparesis secondary to cerebral vascular accident. In patients with hemiplegia, postural sway is increased and often displaced laterally over the non-affected leg, reflecting asymmetry in lower extremity weight bearing during standing balance. Human balance is a complex motor control task, requiring integration of sensory information, neural processing, and biomechanical factors. Limits of stability (LOS) is a one of the biomechanical factors. The purposes of this study were to establish the influence of asymmetrical weight-bearing on the LOS of independent ambulatory hemiparetic patients. The subjects of this study were 29 hemiparetic patients (18 males, 11 females) being treated as admitted or out patients at Young-Nam University Hospital and Taegu Catholic University Hospital, all of whom agreed to participate in the study. Participants were asked to lean and displace their center of gravity (COG) as far as possible in directions to the sides and front of the body. The LOS and weight-bearing ratio were measured with a Balance Performance Monitor (BPM) Dataprint Software Version 5.3. In order to assure the statistical significance of the results, the independent t-test and a Pearson's correlation were applied at the .05 and .01 level of significance. The results of this study were as follows: 1) There were statistically significant differences in anteroposterior LOS according to the cause of brain demage (p<.01). 2) There were statistically significant differences in mediolateral LOS according to the hemiparetic side (p<.05). 3) There were statistically significant differences in anteroposterior and mediolateral LOS according to the brain operation (p<.01). 4) The mediolateral LOS significantly correlated with weight-bearing ratio (p<.01).

• 응용통계연구
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• 제33권2호
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• pp.161-170
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• 2020

${\bar{X}}-S^2$ 관리도는 공정 평균과 산포의 변화를 동시에 탐지하는 전통적인 관리도들 중 하나이다. 일반적으로 사용하는 ${\bar{X}}-S^2$ 관리도의 설계 방법은 병행하는 관리도의 오경보율은 주어진 값을 만족하면서 각 관리도는 동일한 개별적인 오경보율을 갖도록 설정하는 것이다. 이 논문에서는 각 관리도의 개별 오경보율을 다르게 설정하고 이것이 ${\bar{X}}-S^2$ 관리도의 성능에 어떠한 영향을 주는지 살펴보았다. 이를 위해 ${\bar{X}}$ 관리도의 오경보율을 S² 관리도의 오경보율에 γ배한 경우를 고려하였고, γ값에 따른 ${\bar{X}}-S^2$ 관리도 성능을 비교하였다. 관리도의 성능을 평가하는 측도로는 특정한 변화에 대한 성능을 판단하는 경우 이상상태에서의 평균런길이를 사용하였고, 전반적인 성능을 판단하는 경우 RMI(relative mean index)를 사용하였다.

• 응용통계연구
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• 제33권4호
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• pp.451-466
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• 2020

CCC-r 관리도는 불량률이 매우 낮은 고품질 공정을 관리하는 데 효율적이라고 알려져 있다. 대부분의 공정에서 공정 모수의 값은 알려져 있지 않기 때문에 제1국면에서 이를 추정해야 하는데, 표본의 크기가 충분히 크지 않은 경우 추정 오차가 발생하여 원하는 관리상태에서의 성능을 만족하지 못하는 경우가 발생한다. 뿐만 아니라 제1국면에서 추출하는 표본에 따른 산포로 인하여 관리상태일 때의 성능의 산포 또한 커지게 된다. 이러한 문제를 해결하기 위해 이 논문에서는 관리상태일 때 신호까지의 평균관측개수가 사전에 정한 확률로 목표하는 값보다 큰 값을 갖도록, 붓스트랩 알고리즘을 사용하여 CCC-r 관리도의 관리한계를 조정하는 절차를 제안하였다. 이때 고품질 공정에 적용하기 위하여 최대우도추정량 대신 베이즈추정량을 사용하여 불량률을 추정하였다. 다양한 상황에 대해 모의실험을 수행한 결과, 제안된 절차는 CCC-r 관리도의 관리상태 성능을 크게 향상시킴을 알 수 있었다.

• 한국도로학회논문집
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• 제14권5호
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• pp.179-188
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• 2012

PURPOSES: The aim of this study is to analyze overloading control effectiveness of enforcing overweighted vehicles using HS-WIM (High-Speed Weigh-in-Motion) at main lane of expressway. METHODS: To analyze the weight distribution statistically, HS-WIM system should has an appropriate weighing accuracy. Thus, the weighing accuracy of the two HS-WIM systems was estimated by applying European specifications and ASTM (American Standards for Testing and Materials) for WIM in this study. Based on the results of accuracy test, overweight enforcement system has been operated at main lanes of two expressway routes in order to provide weight informations of overweighted vehicle in real time for enforcement squad. To evaluate the overloading control effectiveness with enforcement, traffic volume and axle loads of trucks for two months at the right after beginning of the enforcement were compared with data set for same periods before the enforcement. RESULTS: As the results of weighing accuracy test, both WIM systems were accepted to the most precise type that can be useful to applicate not only statistical purpose but enforcing on overweight vehicles directly. After the enforcement, the rate of overweighted trucks that weighed over enforcement limits had been decreased by 27% compared with the rate before the enforcement. Especially, the rate of overweighted trucks that weighed over 48 tons had been decreased by 91%. On the other hand, in counterpoint to decrease of the overweighted vehicle, the rate of trucks that weighed under enforcement limits had been increased by 7%. CONCLUSIONS: From the results, it is quite clear that overloading has been controlled since the beginning of the enforcement.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.717-724
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• 2023

An essential step in evaluating and comparing the performance of two passive radiation dosimeter types, thermosluminescent (TLD) and optically stimulated luminescence (OSL), used by workers in environments with ionizing radiation for individual radiological monitoring and control of external exposure at various times (cumulative dose for 1 month), is to compare the measured dose accuracy, energy response, and coefficient of variation. In fact this performance study consists in determining the accuracy of both R(10) and R(0.07) which are considered as the ratios of the measured dose (Hp(10) or Hp(0.07)) to the delivered dose (Hp(10) or Hp(0.07)) for each photon energy. The validity of the results of this test is based on the acceptance limits of the ICRP and the international standard IEC-62387. The relative energy response used is normalized to the ¹³⁷Cs 662 keV energy to find which energy response is closest to the ideal case, and the coefficient of variation that allows to determine the statistical fluctuation of the Hp(10) and Hp(0.07) doses. The results of the accuracy test for the OSL and TLD dosimeters are acceptable because they fall within the ICRP limits. For the energy response, the OSL performs better than the TLD for Hp(10) and Hp(0.07), and for the coefficient of variation, the OSL satisfies the requirements of ISO 62387 for both Hp(10) and Hp(0.07), while the TLD satisfies these requirements only for the measurement of Hp (0.07).

• 한국방사선학회논문지
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• 제17권3호
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• pp.401-410
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• 2023

방사선사는 영상진단장치를 담당하는 직종으로 적절한 업무 수준을 제시하여 국민건강 증진에 기여하여야 한다. 이를 위해 업무에 따른 인체 유해성 평가, 설문지를 통한 통계 평가, 국내·외 동향을 통해 적절한 업무 수준을 제시하고자 한다. 인체 유해성 평가의 경우 방사선 피폭을 고려하여 42.6 %, 차폐체 작업은 69.7 %, MRI의 경우 검사실 체류시간이 최대 15분, 30회를 초과하지 않도록 조절하여야 한다. 설문통계에서는 근로시간 대비 업무량 및 난이도가 높아 신체적, 정신적 부담이 증가됨을 확인할 수 있었으며, 국내·외 동향을 통해 국내 방사선사의 검사 기준을 36.8 %까지 조절하여 방사선 검사의 질적 향상을 통해 국민건강증진을 도모하여야 한다.