• Journal of Korean Society of Transportation
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• v.28 no.3
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• pp.119-130
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• 2010

Reconstruction analysis of traffic accident is done by analyzing diverse data such as the road, accident traces and damage on the automobile. Most data can be a variable in the process of analysis, and measurement error of the data occurs from the investigator, tool and the given environment. Therefore, accident analysis always has some risks of measurement uncertainty. This research quantify the uncertainty in traffic accident analysis by conducting repetitive measurement experiments for variables with high probability of uncertainly such as length (i.e. geometric structure of the road, tire marks) and coefficient of friction. This paper also suggests an analysis result for the uncertainly of photographic observation of automobile crush measurement. These statistical distributions can help determine appropriate ranges for the input data in order to estimate the accident reconstruction uncertainty.

• Journal of the Korean Vacuum Society
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• v.18 no.6
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• pp.418-425
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• 2009

To get the stable and optimized proton beam in the KIRAMS-13 cyclotron which installed in the regional cyclotron center, it is necessary to measure the transverse profile of proton beam. Beam Induced Fluorescence monitor is one of the non-destructive methods to measure the beam profiles, and it has many advantages such as a simple structure, real-time measurement, and minimum energy loss. The objective of this research is the design and development of Beam Induced Fluorescence monitor to measure the proton beam profiles in the KIRAMS-13 cyclotron.

• The Journal of the Acoustical Society of Korea
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• v.14 no.2
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• pp.5-15
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• 1995

An application of the cross correlation technique by adopting ultrasonic waves for water pipe flow measuring purpose is studied. It is a non-intrusive flow metering method by determining the time of the flight of the flow turbulent noise and its non-obstructing mechanism enables to reduce process energy loss due to the flowmeter obstruction. A digital signal processor for the purpose of the real time Fourier transform was employed for the fast time calculation of the flow velocity. The overall accuracy was found as about $1\%$ for flow velocities from 0.25 m/s up to 16 m/s and for the pipe inside diameters from 50mm to 248mm. The cross correlation technique can be used for the tap water utility including most common liquid flows.

• Journal of the Korean Magnetics Society
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• v.12 no.4
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• pp.149-153
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• 2002

Flux-gate magnetometer has been still used for low field magnetic field measurement with portability, low power consumption, and high reliability. In many applications, flux-gate magnetometer measures not absolute values but changes of the earth magnetic field. For the eia magnetic field change measurements, we have constructed a high sensitive 3-axis flux-gate magnetometer of which measuring ranges is ${\pm}$1000 nT and noise level is 5pT/√㎐ at 1 ㎐. Using this magnetometer, we can compensate the earth magnetic field of ${\pm}$50,000 nT with successive approximation methods using microcomputer. After earth magnetic field compensation, we could measure earth magnetic field changes with ${\pm}$100 nT measuring ranges.

• Journal of the Korean Society of Clothing and Textiles
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• v.12 no.2 s.27
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• pp.189-199
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• 1988

착의행동을 일으키는 전단계의 감각으로서 국소의 냉감각과 체표 각 부위에 있어서의 냉점분포에 대하여 측정을 하였다. 피험자는, 냉점분포 측정에 한국인 여자 대학생 30명, 냉감각측정에는 한국인과 일본인 여자 대학생 8명을 대상으로 하였으며, 환경조건은 실온 $29^{\circ}C{\pm}1^{\circ}C$, 상대습도 $55{\pm}5\%$의 인공기후실로 하였다. 냉자격으로서는 $0^{\circ}C$의 냉각이 사용되었으며, 측정부위는 냉점분포 측정의 경우 체표 20부위, 냉감각 측정의 경우 체표 13부위로 하였고 측정결과는 다음과 같다. (1) 체표면의 냉점분포 밀도는 부위에 따라서 다르며, 체간부와 두부는 냉점분포 밀도가 높고 말단부에 갈수록 그 분포가 낮아졌다. 특히 가장 민감한 부위는 복부였다. 즉 체간부와 두부는 중핵온을 일정하게 보지하므로서 중핵부 체내온의 변화를 방어하기 위한 온도 수용 부위로서의 역할을 하고 있으며, 말초부는 냉점분포가 낮아서 기온에 따라 체표온(외각온)을 광범위하게 변화시키는 사지부의 온도정보입력의 역할을 담당하고 있다고 하겠다. (2) 각 부위에 있어서의 냉감각 순위는 일본인과 한국인 피험자간에 고도의 상관(r=0.93)이 보여져, 양 피험자군간에 차이는 볼 수 없었다. 3) 냉점분포 밀도가 높은 부위인 복부는 냉감각도 가장 민감하였으며, 냉점분포 밀도가 낮은 하퇴부는 냉감각 감수성도 낮게 나타났다. (4) 발바닥과 손바닥은 냉감각을 민감하게 느끼는 부위임에도 불구하고 냉점분포 밀도가 낮게 나타났으며, 이는 특수성이 있는 부위로서 주목되어지는 결과라고 하겠다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.4
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• pp.378-384
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• 2011

During the flight test of KSLV-I, various sensors are installed in the launch pad and the flame deflector to measure the flame characteristics and their influences on the launch complex when a launch vehicle lifts off. Parameter Measurement System is responsible for acquiring the above flight test data. The measurement methodology such as the configuration of measurement system, sensor locations and data acquisition procedures are presented. And this paper compares and explains the characteristics of data sets measured during two flight tests.

• The Journal of Society for e-Business Studies
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• v.18 no.1
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• pp.97-105
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• 2013

In the e-business domain where data objects are quantitatively large, measuring similarity to find the same or similar objects is important. It basically requires comparing and computing the features of objects in pairs, and therefore takes longer time as the amount of data becomes bigger. Recent studies have shown various algorithms to efficiently perform it. Most of them show their performance superiority by empirical tests over some sets of data. In this paper, we introduce those data sets, present their characteristics and the meaningful threshold values that each of data sets contain in nature. The analysis on practical data sets with respect to their threshold values may serve as a referential baseline to the future experiments of newly developed algorithms.

• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.387-394
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• 2011

Standard devices and procedures for measuring the pumping speed, one of the most important parameters indicating the operation performance of the vacuum pump, have been developed and widely utilized. Though the standard system has a firm theoretical basis, it is, sometimes, inevitable to alter something in the system for a practical purpose compared with ideal conditions, which may lead to a large measurement error. In this paper, characteristics and systematic errors of various ideal or practical schemes for measuring the pumping speed are analyzed, and compensation terms are proposed.

• The Journal of the Acoustical Society of Korea
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• v.29 no.6
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• pp.355-364
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• 2010

Considering biological safety, it is very important to measure acoustic power from ultrasonic array probe for diagnostic ultrasound imaging applications. In this paper, to measure acoustic power from each element on array probe for ultrasonic diagnostic equipment, we reconstruct and automate the acoustic power measurement system. The acoustic power from linear, phased and curved array were measured and analyzed. As a result of measurement, the effects caused by directivity of sound beam from curved array were founded. To remove these effects, we developed and applied the correction model. The proposed system is useful to evaluate characteristics of the acoustical output power of array probe.

• Journal of Korean Home Economics Education Association
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• v.29 no.1
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• pp.35-56
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• 2017

The purposes of this study were to develop an instrument to examine the latent domains to measure H-PCK and verify the reliability and validity of the instrument. To accomplish these purposes, instrument item development, content validity, pilot study, and main study were conducted. The results were as follows. First, based on a review of extant literature, 29 items for H-PCK were developed. Seven items were deleted from the original instrument after determining content validity by 10 in-service Home Economics teachers, which resulted in the 22 items of 3 domains(Knowledge of perspective on Home Economics Education(KP), Knowledge of Home Economics curriculum(KC), Knowledge of Home Economics instructional strategies(KI)). Second, data were collected from 137 Home Economics teachers via mail survey for pilot study to establish reliabilities for each individual domain and across the domains based on Cronbach's ${\alpha}$ and item-total correlation. The result showed good reliabilities in the cut-off value of .7 and .5 for Cronbach's ${\alpha}$ and for item-total correlation respectively. Third, the main study was performed with 220 Home Economics teachers via e-mail survey and the reliability and validity tests were conducted. The reliability test results showed good reliabilities. The model for confirmatory factor analysis(CFA) provided a good fit to the data (e.g., CFI=.92, RMSEA=.06, SRMR=.05) to evaluate construct validity. The three domains of KP, KC, and KI demonstrated the acceptable convergent and discriminant validities in each individual domain and over domains. Thus, the instrument in this study may be utilized to measure H-PCK. Finally, criterion-related validity was performed to examine the extent to which the three domains are related to teacher efficacy with Pearson correlation (${\rho}$). It was relatively highly correlated at ${\rho}=.7$. In addition, the higher H-PCK the Home Economics teachers had, the higher teacher efficacy they had. The final instrument consisting of 22 items from 3 domains were determined through the entire procedure.