• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.762-767
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• 2003

The railroad is a means of large transportation which has many talents such as a safety and a regularity. That is a results from various confidential performance tests and evalutions of the system. The railroad system consist of various subsystems - vehicle, power spply, signal communications, track structures, operations, etc. Among them as an item of safety evaluation there is a measurement of wheel/rail force, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more important in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, it is introduced to preprocess the wheelset for measuring wheel/rail force of Gwangiu EMU, such as to treat a measuring wheelset its finite element analysis, adhesion of strain gauges and static load test.

• Applied Science and Convergence Technology
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• 제23권3호
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• pp.103-112
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• 2014

The Korea Research Institute of Standards and Science (KRISS) has three major vacuum systems: an ultrasonic interferometer manometer (UIM; Section II, Figs. 1 and 2) for a low vacuum, a static expansion system (SES; Section III, Figs. 3 and 4) for a medium vacuum, and an orifice-type dynamic expansion system (DES, Section IV, Figs. 5 and 6) for high and ultra-high vacuum systems. For each system, explicit measurement model equations with multiple variables are given. According to ISO standards, all of these system variable errors were used to calculate the expanded uncertainty (U). For each system, the expanded uncertainties (k = 1, confidence level = 95%) and relative expanded uncertainty (expanded uncertainty/generated pressure) levels are summarized in Table 4. Within the uncertainty limits, our bilateral and key comparisons [CCM.P-K4 (10 Pa to 1 kPa)] are extensive and in good agreement with those of other nations (Fig. 8 and Table 5).

• 한국정밀공학회지
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• 제14권10호
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• pp.15-27
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• 1997

Quasti-static cutting force variations in milling process are measured indirectly using spindle motor current. Quasi-static sensitivity of the spindle motor current is higher than that of the feed motor current. Magnitude of the spindle motor current is independent of cutting direction. The linear relationship between the cutting force and the spimdle motor RMS current at various spindle rotational speed is obtained. Frequency/ Voltage(F/V) converter voltage is measured to identify the spindle speed and to determine the cutting force at various spindle speeds. Overload on the tool during milling process can be detected using the proposed indirect cutting force measurement. Based on these measurements, cutting force is regulated at a constant level by feedrate control.

• 스마트미디어저널
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• 제4권2호
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• pp.34-45
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• 2015

윈도우는 국내에서 가장 많이 사용되는 운영체제이기 때문에 윈도우용 소프트웨어를 대상으로 불법 복제가 많이 이루어지고 있고 불법 복제로 인해 소프트웨어 저작권이 침해될 수 있다. 이를 보호하기 위해서 저작권 보호 방법 중 하나인 소프트웨어 버스마크를 사용한다. 소프트웨어 버스마크는 소프트웨어로부터 특정 정보들을 추출하여 소프트웨어간 도용 여부를 판별할 수 있는 기술이며 대상 소프트웨어로 부터 특정 정보를 추출하는 방법에 따라 정적 버스마크와 동적 버스마크로 구별된다. 정적 버스마크와 동적 버스마크는 서로 장단점을 가지고 있지만 본 논문에서는 API 기반 동적 버스마크를 이용한 유사도 측정 기법을 제안하고, 동적 버스마크의 추출 과정을 설명한다. 또한 실험을 통해 제안하는 동적 버스마크의 유사도 측정 기법이 신뢰성과 강인성을 만족하는 것을 확인할 수 있었으며 기존 동적 버스마크의 유사도 측정 기법보다 제안하는 동적 버스마크의 성능이 향상 된 것을 확인할 수 있었다.

• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.1-19
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• 2002

The purpose of this study is to identify influence that eye movement have an effect on postural control and balance performance by plegia side of the impaired patients of central nervous system. Subjects are patients with the impairment of central nervous system and experimental and control groups are forty people and thirty people seperatively, Total subjects were selected to seventy persons, but twelve persons of experimental group quit during the experimental periods and eight persons of control group did not measure after exercise. Therefore, twenty eight persons of experimental group and twenty two persons of control group were selected in this study and experimental group peformed eye movement for eight weeks according to the exercise program of this study. The measurement of dependent variable is right static balance, left static balance, bilateral static balance, and bilateral dynamic balance before exercise and after eighth week of exercise, examiner again measured and analyzed the results. The results were as follows: 1. As the result of comparing balance performance ability after test of the experimental and control group with right hemiplegia and control group, all of static balance performance ability of right side (p < 0.01), static balance performance ability of left side (p < 0.01), static balance performance ability of bilateral side(p < 0.01), dynamic balance performance ability of bilateral side(p < 0.05) of experimental group were statistically greater improved than those of the control group. 2. As the result of comparing balance performance ability after test of the experimental and control group with left hemiplegia and control group, all of static balance performance ability of right side (p < 0.01), static balance performance ability of left side (p < 0.01), static balance performance ability of bilateral side(p < 0.05), dynamic balance performance ability of bilateral side(p < 0.05) of experimental group were statistically greater improved than those of the control group.

• Journal of Positioning, Navigation, and Timing
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• 제9권3호
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• pp.273-284
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• 2020

The performance of Global Navigation Satellite System (GNSS) chipset and Inertial Measurement Unit (IMU) sensors embedded in smartphones for location-based services (LBS) is limited due to the economic reasons for their mass production. Therefore, it is necessary to efficiently process the output data of the smartphone's embedded sensors in order to derive the optimum navigation values and, as a previous step, output performance of smartphone embedded sensors needs to be verified. This paper analyzes the navigation performance of such devices by processing the raw measurements data output from smartphones. For this, up-to-dated versions of smartphones provided by Samsung (Galaxy s10e) and Xiaomi (Mi 8) are used in the test experiment to compare their performances and characteristics. The GNSS and IMU data are extracted and saved by using an open market application software (Geo++ RINEX Logger & Mobile MATLAB), and then analyzed in post-processing manner. For GNSS chipset, data is extracted from static environments and verified the position, Carrier-to-Noise (C/N₀), Radio Frequency Interference (RFI) performance. For IMU sensor, the validity of navigation and various location-based-services is predicted by extracting, storing and analyzing data in static and dynamic environments.

• 한국정보통신학회논문지
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• 제13권10호
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• pp.2147-2153
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• 2009

저가격형으로 프로토타잎 하이브리드형 리니어 펄스 모터(LPM)가 편측형으로 설계되었다. 모터의 정특성 및 동특성 측정위한 측정기기를 설계 제안하였다. 실험측정결과 프로토타잎 리니어 펄스 모터의 정특성 및 동특성을 구체적인 추력의 값으로 확인하였다. 프로트타잎 리니어 펄스 모터를 구형파와 마이크로스텝 구동으로 구동하여 각각의 경우의 추력의 변화를 확인하였다. 실험결과 마이크로스텝구동방식에서 추력리플이 현저히 줄어든 것을 확인할 수 있었다.

• 산업기술연구
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• 제22권A호
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• pp.169-176
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• 2002

The purpose of this paper is to investigate for strain measurement of concrete pavement slab at field. The early-age behaviors of concrete pavement were measured using the strain gages. From the static and dynamic wheel loading tests, the outputs from each gages were recorded. The measured data, also, was compared to those from finite element analysis. The static wheel loading tests were performed in twice, and the dynamic wheel loading tests were performed at the speed 10km-50km. The results could be summarized as follows: To embed the strain gage accurately and stably in concrete pavement, a chair and protective box must be used. The protective box must not be affected from the outside vibrating. From the results of early-age stram measurement, it was found that the strain varied at the maximum value of $180{\mu}{\varepsilon}$ From the results of static wheel loading tests, A1, A2 and B gages generally developed a consistent tendency When comparing the results from the measured at field and the calculated by FEM analysis, the data of A1 and B gages were similar to that from theory. The values from the field test were generally higher than that from the theory. From the results of dynamic wheel loading tests, it was known that the measured strain at field became smaller as the truck speed became faster, Indicating the maximum at the range of $12{\sim}13{\mu}{\varepsilon}$.

• 한국소음진동공학회논문집
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• 제13권2호
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• pp.132-143
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• 2003

Viscoelastic components for vibration isolation or shock absorption in automobiles, machines and buildings are often subject to a high level of static deformation. From the dynamic design point of view, it is requisite to predict dynamic complex stiffness of viscoelastic components accurately and efficiently. To this end, a systematic procedure for complex modulus measurement of the viscoelastic material under large static deformation is often required in the industrial fields. In this paper, dynamic test conditions and procedures for the viscoelastic material under small oscillatory load superimposed on large static deformation are discussed. Various standard test methods are investigated in order to select an adequate test methodology. The influence of fixed boundary condition in the compression tests upon complex stiffness are investigated and an effective correction technique is proposed. Then the uniaxial tension and compression tests are performed and its results are compared with analysis results from conventional constitutive models.

• The Journal of Korean Physical Therapy
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• 제23권6호
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• pp.37-42
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• 2011

Purpose: The aim of this study is to suggest the basic materials for proposing effective and efficient methods when stretching by measuring isokinetic muscular strength according to static, dynamic and PNF stretching. Methods: This study was conducted on 45 healthy persons (male and female) in their twenties who are attending universities. The subjects are randomly divided into three (3) groups, and static stretching is applied in group 1, dynamic stretching is applied in group 2 and PNF stretching is applied in group 3. After carrying out static, dynamic and PNF stretching, peak torque was measured using isokinetic muscular strength measurement. Results: According to the results, at $60^{\circ}$/sec and $180^{\circ}$/sec isokinetic peak torque of the knee joint according to types of stretching, the largest changes were shown in Group 2 extension and flexion, and the least changes were shown in Group 1. There were significant differences among the three groups (p<0.05), and the result of after-analysis by LSD showed that there were significant differences between Groups 1 and 2, and Groups 1 and 3 (p<0.05). Conclusion: The intention of this study was to determine the peak torque using Cybex after applying three stretching methods to hamstring muscles, and the case of dynamic and PNF stretching was found to be more significant in both the $60^{\circ}$/sec and $180^{\circ}$/sec angular speeds than that of static stretching. Using the results of such studies, if dynamic and PNF stretching are applied together with warming-up before performing sports, the risk of suffering wounds would reduce and the exactness of sports would increase.