• Title/Summary/Keyword: time scale

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Psychometric Testing of the Korean Version of Templer's Death Anxiety Scale among Older Adults (노인 대상 한국형 Templer의 죽음불안도구 신뢰도 및 타당도)

  • Hwang, Hyenam
    • Journal of East-West Nursing Research
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    • v.25 no.1
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    • pp.26-32
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    • 2019
  • Purpose: The purpose of this methodological study was to examine the validity and reliability of a translated Korean version of Templer's death anxiety scale among older adults. Methods: The translated Korean scale was administered to 203 older people who aged over 65 years. Exploratory factor analysis was utilized to assess the factor structure of the scale. Internal consistency of the scale was determined using Cronbach's ${\alpha}$ and Guttman's split-half coefficient. Results: Factor loadings of the scale ranged from .43 to .86. The scale showed good internal consistencies of both total scale (13 items, ${\alpha}=.83$) and three sub-scales: meaning of death (6 items, ${\alpha}=.77$), death-related event (5 items, ${\alpha}=.72$), and time of death (2 items, ${\alpha}=.80$). The concurrent validity compare with Fear of Death Scale was significant. The Cronbach's alpha and Guttman's split-half coefficient were .83 and .80, respectively. Conclusion: The findings of this study demonstrate that the Korean version of Templer's death anxiety scale had satisfactory validity and reliability to measure death anxiety among Korean older people.

Multiscale method and pseudospectral simulations for linear viscoelastic incompressible flows

  • Zhang, Ling;Ouyang, Jie
    • Interaction and multiscale mechanics
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    • v.5 no.1
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    • pp.27-40
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    • 2012
  • The two-dimensional incompressible flow of a linear viscoelastic fluid we considered in this research has rapidly oscillating initial conditions which contain both the large scale and small scale information. In order to grasp this double-scale phenomenon of the complex flow, a multiscale analysis method is developed based on the mathematical homogenization theory. For the incompressible flow of a linear viscoelastic Maxwell fluid, a well-posed multiscale system, including averaged equations and cell problems, is derived by employing the appropriate multiple scale asymptotic expansions to approximate the velocity, pressure and stress fields. And then, this multiscale system is solved numerically using the pseudospectral algorithm based on a time-splitting semi-implicit influence matrix method. The comparisons between the multiscale solutions and the direct numerical simulations demonstrate that the multiscale model not only captures large scale features accurately, but also reflects kinetic interactions between the large and small scale of the incompressible flow of a linear viscoelastic fluid.

The Effect of Scale Parameter in Designing Reliability Demonstration Test for Lognormal Lifetime Distribution (대수정규 수명분포를 갖는 제품에 대한 신뢰성 입증시험에서 척도모수의 영향분석)

  • Kwon, Young Il
    • Journal of Applied Reliability
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    • v.14 no.1
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    • pp.53-57
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    • 2014
  • In the fields of reliability application, the most commonly used test methods for reliability demonstration are zero-failure acceptance tests since they require fewer test samples and less test time compared to other test methods that guarantee the same reliability with a given confidence level. For products with lognormal lifetime distribution, the value of scale parameter is usually assumed to be known in designing reliability demonstration tests. It is important to select correct values of scale parameters to guarantee the specified reliability with given confidence level exactly. The effect of using wrong values of scale parameters in designing reliability demonstration test for products with lognormal lifetime distribution is examined and selecting proper values of scale parameters for conservative reliability demonstration is discussed.

A Study of CaSO4 Scale Formation and Heat Transfer in a Vertical Tube Evaporator (수직 증발관에서 CaSO4 Scale 형성과 열전달에 관한 연구)

  • Hong, Choonkeun;Choi, Mansoo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.11
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    • pp.1363-1370
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    • 1999
  • A study of scaling and heat transfer has been carried out for a vertical tube evaporator in which $CaSO_4$ saturated water flows upward. Experimental apparatus including vacuum chambers and heaters has been designed and manufactured to study scaling phenomena for three different pressures(1atm, 0.27atm and 0.16atm). Overall heat transfer coefficients have been measured and shown to decrease with time as scaling proceeds. After the end of experiments, the vertical tube has been cut to measure the thickness of scale at different heights. Below the height where the bulk fluid temperature does not reach saturated temperature, the thickness of scale increases, however, beyond that height occurring saturated condition, the thickness does not vary much or even decreases a little. The measured fouling resistances also support these variations of scale thickness.

Effect of Direction to be Used for the Timed Up and Go Test on Walking Time in Stroke Patients (일어서서 걷기 검사 시 회전 방향이 뇌졸중 환자의 보행 시간에 미치는 영향)

  • Lee, Geon;Cho, Cheol-hoon;Lim, Kyung-jin;Lee, Joo-hyun;Yoon, Gyu-ri;Woo, Young-keun
    • Physical Therapy Korea
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    • v.23 no.2
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    • pp.11-19
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    • 2016
  • Background: In the stroke patients with the characteristics of hemiplegic gait, turning direction of the affected and unaffected side influences turning time. Therefore, it is important to investigate the walking response to turning directions in stroke patients. Objects: This study aimed to measure the walking time while turning direction in hemiplegic patients depending on balance ability measured by Berg Balance Scale. Methods: A group of forty-five subjects with stroke (Berg Balance Scale score${\geq}46$ were twenty-eight, Berg Balance Scale score${\leq}45$ were seventeen) were enrolled in this study. Subjects were asked to perform the Timed Up and Go test. Testing indications included two directions for turning in each subject. These indications were for turning toward the affected and unaffected side in stroke patients. The duration of total analysis duration, sit to stand phase, stand to sit phase, mid-turning phase, and end turning phase were recorded. The obtained data were analyzed by using paired t-test and Wilcoxon signed rank test in the group that are below and above 45 points of Berg Balance Scale score. The significance level was set at ${\alpha}=.05$. Results: There were significant increase time in the analysis duration and end turning phase duration while subjects were turned the unaffected side in stroke patients that presented a Berg Balance Scale score${\leq}45$ (p<.05). However, the comparison between the affected side and the unaffected side in the stroke patients with Berg Balance Scale score${\geq}46$, revealed no significant differences of the measured parameters. Conclusion: This finding should be suggested in the specific definition of turning direction for evaluation with Timed Up and Go test in the Berg Balance Scale score${\leq}45$, and other intervention for hemiplegic patients need to be suggested the direction of turning during walking training program.

Computer Vision-based Continuous Large-scale Site Monitoring System through Edge Computing and Small-Object Detection

  • Kim, Yeonjoo;Kim, Siyeon;Hwang, Sungjoo;Hong, Seok Hwan
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.1243-1244
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    • 2022
  • In recent years, the growing interest in off-site construction has led to factories scaling up their manufacturing and production processes in the construction sector. Consequently, continuous large-scale site monitoring in low-variability environments, such as prefabricated components production plants (precast concrete production), has gained increasing importance. Although many studies on computer vision-based site monitoring have been conducted, challenges for deploying this technology for large-scale field applications still remain. One of the issues is collecting and transmitting vast amounts of video data. Continuous site monitoring systems are based on real-time video data collection and analysis, which requires excessive computational resources and network traffic. In addition, it is difficult to integrate various object information with different sizes and scales into a single scene. Various sizes and types of objects (e.g., workers, heavy equipment, and materials) exist in a plant production environment, and these objects should be detected simultaneously for effective site monitoring. However, with the existing object detection algorithms, it is difficult to simultaneously detect objects with significant differences in size because collecting and training massive amounts of object image data with various scales is necessary. This study thus developed a large-scale site monitoring system using edge computing and a small-object detection system to solve these problems. Edge computing is a distributed information technology architecture wherein the image or video data is processed near the originating source, not on a centralized server or cloud. By inferring information from the AI computing module equipped with CCTVs and communicating only the processed information with the server, it is possible to reduce excessive network traffic. Small-object detection is an innovative method to detect different-sized objects by cropping the raw image and setting the appropriate number of rows and columns for image splitting based on the target object size. This enables the detection of small objects from cropped and magnified images. The detected small objects can then be expressed in the original image. In the inference process, this study used the YOLO-v5 algorithm, known for its fast processing speed and widely used for real-time object detection. This method could effectively detect large and even small objects that were difficult to detect with the existing object detection algorithms. When the large-scale site monitoring system was tested, it performed well in detecting small objects, such as workers in a large-scale view of construction sites, which were inaccurately detected by the existing algorithms. Our next goal is to incorporate various safety monitoring and risk analysis algorithms into this system, such as collision risk estimation, based on the time-to-collision concept, enabling the optimization of safety routes by accumulating workers' paths and inferring the risky areas based on workers' trajectory patterns. Through such developments, this continuous large-scale site monitoring system can guide a construction plant's safety management system more effectively.

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EETS : Energy- Efficient Time Synchronization for Wireless Sensor Networks (무선 센서 네트워크에서 에너지 효율성을 고려한 시간 동기 알고리즘)

  • Kim, Soo-Joong;Hong, Sung-Hwa;Eom, Doo-Seop
    • Journal of IKEEE
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    • v.11 no.4
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    • pp.322-330
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    • 2007
  • Recent advances in wireless networks and low-cost, low-power design have led to active research in large-scale networks of small, wireless, low power sensors and actuators, In large-scale networks, lots of timing-synchronization protocols already exist (such as NTP, GPS), In ad-hoc networks, especially wireless sensor networks, it is hard to synchronize all nodes in networks because it has no infrastructure. In addition, sensor nodes have low-power CPU (it cannot perform the complex computation), low batteries, and even they have to have active and inactive section by periods. Therefore, new approach to time synchronization is needed for wireless sensor networks, In this paper, I propose Energy-Efficient Time Synchronization (EETS) protocol providing network-wide time synchronization in wireless sensor networks, The algorithm is organized two phase, In first phase, I make a hierarchical tree with sensor nodes by broadcasting "Level Discovery" packet. In second phase, I synchronize them by exchanging time stamp packets, And I also consider send time, access time and propagation time. I have shown the performance of EETS comparing Timing-sync Protocol for Sensor Networks (TPSN) and Reference Broadcast Synchronization (RBS) about energy efficiency and time synchronization accuracy using NESLsim.

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The Study for Software Future Forecasting Failure Time Using ARIMA AR(1) (ARIMA AR(1) 모형을 이용한 소프트웨어 미래 고장 시간 예측에 관한 연구)

  • Kim, Hee-Cheul;Shin, Hyun-Cheul
    • Convergence Security Journal
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    • v.8 no.2
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    • pp.35-40
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    • 2008
  • Software failure time presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing. For data analysis of software reliability model, data scale tools of trend analysis are developed. The methods of trend analysis are arithmetic mean test and Laplace trend test. Trend analysis only offer information of outline content. In this paper, we discuss forecasting failure time case of failure time censoring. The used software failure time data for forecasting failure time is random number of Weibull distribution(shaper parameter 1, scale parameter 0.5), Using this data, we are proposed to ARIMA(AR(1)) and simulation method for forecasting failure time. The practical ARIMA method is presented.

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Ultrastructure on the Forming of the Scale and Socket in the Wing of the Pieris rapae L. (배추흰나비(Pieris rapae L.) 날개의 인편(鱗片)과 소켓트의 형성(形成)에 관한 미세구조(微細構造))

  • Kang, Seong-Hoon;Kim, Chang-Shik;Kim, Woo-Kap
    • Applied Microscopy
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    • v.19 no.2
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    • pp.27-42
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    • 1989
  • The forming process of scale and socket of Pieris rapae L. during in 30 hr. pupa to in adult was morphologically investigated with scanning electron microscopy and transmission electron microscopy. 1. The scale forming cells which were distinguished from other epidermal cells were first observed in 30 hr. pupa. In the aspect that scale forming cell beared some morphological relations to socket forming cells and in the distribution of its organelles, scale forming cell was divided into three regions-basal region in which nucleus located, neck region which was surrounded by socket forming cells and scale region that was the cytoplasmic projection region over the wing surface. In process of the development of scale forming cell neck region and scale region were extended into the molting space and at this time, the changes of surface structure of scale region have occurred initially. 2. There was a more distinct process that scale region changed into the scale. Scale region which was first originated as clublike projection of the cell body was subsequently elongated and flattened out by broadening of the cytoplasm. After that, in the surface of scale were formed longitudinal ridges and microribs. In the late pupa, the cytoplsam of scale region have autolyzed by lysosome-like bodies and at length, scale which had air spaces, trabecula, pigment granules, longitudinal ridges and transverse ridges. 3. The major protion of socket forming cell located beside neck region of scale forming cell under the wing surface but the processing portion of the cell lay over the wing surface, suggesting that socket forming cells have actively processing. In extending to the molting space of neck and scale region, socket forming cells developed to the molting space and constructed socket.

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Gate-Length Dependent Cutoff Frequency Extraction for Nano-Scale MOSFET (Nano-Scale MOSFET의 게이트길이 종속 차단주파수 추출)

  • Kim, Joung-Hyck;Lee, Yong-Taek;Choi, Mun-Sung;Ku, Ja-Nam;Lee, Seong-Heam
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.12
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    • pp.1-8
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    • 2005
  • The gate length-dependence of cutoff frequency is modeled by using scaling parameter equations of equivalent circuit parameters extracted from measured S-parameters of Nano-scale MOSFETs. It is observed that the modeled cutoff frequency initially increases with decreasing gate length and then the rate of increase becomes degraded at further scale-down. This is because the extrinsic charging time slightly decreases, although the intrinsic transit time greatly decreases with gate length reduction. The new gate length-dependent model will be very helpful to optimize RF performances of Nano-scale MOSFETs.