• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1485-1492
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• 2015

This paper proposes a double frequency method using FTP(Fourier Transform Profilometry) in fringe projection techniques for 3D measurement systems. In fringe projection techniques, fringe pattern images are projected and captured, and then object is measured by analysing phase. PMP(Phase Measuring Profilometry) for analysing phase provides high-resolution and is robust to object's reflection and background intensities. However, the measurement range is narrow due to 2π ambiguity. In order to overcome this problem, a double frequency method is often used. This method can widen the range of measurement while maintaining the high-resolution, but the measurement time is taken about twice due to grab 2 times number of images. The proposed double frequency method using FTP requires an additional image for resolving 2π ambiguity. The proposed method effectively reduces the measurement time while maintaining the same accuracy.

• Child Health Nursing Research
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• v.8 no.1
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• pp.67-76
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• 2002

The purpose of this study was to investigate the level of uncertainty and anxiety in families of hospitalized children. Data were collected through self-report questionnaires which were constructed to include parent's perception of uncertainty and state anxiety. The subjects consisted of 126 families of hospitalized children in one university-affiliated hospital in Daegu. The data were analyzed by the SPSS program. The results were as follows; 1. The mean score of uncertainty was 64.70 (Range=31-95). The mean scores of subsets of the uncertainty were followed as: lack of clarity (2.59), unpredictability (2.46), lack of information (2.22) and ambiguity (2.14). 2. The mean score of state anxiety was 47.93 (Range=20-67). 3.The level of uncertainty was positively correlated to the level of state anxiety. 4. The level of anxiety was different depending on their religion and monthly income. The above findings indicated that the level of uncertainty and the state anxiety in families of hospitalized children were positively correlated. Therefore, nursing intervention for reducing uncertainty and anxiety and improving coping method should be provided for families of hospitalized children.

• Journal of Communications and Networks
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• v.7 no.4
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• pp.429-437
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• 2005

Sensor localization has become an essential requirement for realistic applications over wireless sensor networks (WSN). In this paper we propose an ad hoc localization algorithm that is infrastructure-free, anchor-free, and computationally efficient with reduced communication. A novel combination of distance and direction estimation technique is introduced to detect and estimate ranges between neighbors. Using this information we construct unidirectional coordinate systems to avoid the reflection ambiguity. We then compute node positions using a transformation matrix [T], which reduces the computational complexity of the localization algorithm while computing positions relative to the fixed coordinate system. Simulation results have shown that at a node degree of 9 we get $90\%$ localization with $20\%$ average localization error without using any error refining schemes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.3
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• pp.215-226
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• 1999

The experimented rangefinder consist of sets of V/A-Code GPS and sets of L1 C/A-code & carrier phase receivers connected by two spread spectrum radio modems in order to measure relative range and bearing between two ship antennas by real time, comparing and analyzing accuracy of both GPS receivers at the fix point on the land by means of executing zero baseline test by C/A code and by carrier phase as well as measuring distance range 5m, 10m, 15m between each other receivers. The results from the measurement of relative range and bearing are as follows as ;1. According to the results from zero baseline test, the average error by C/A-code receiver is less than 0.1m, which proves theories from published books but when each GPS receivers track different satellites, the range accuracy error becomes up to 100m by means of S/A. Because of this sudden wide range error, rangefinder is not appropriate at relative range measurement without additional modification of the algorism of the GPS receiver itself.2. According to relative range measurement by Carrier Phase and zero baseline test at static condition, the range error is less than 3.5cm in case that it passes more than 5 minutes after GPS sets can track simultaneously more than 6 satellites. Its main reason is understood that the phase center of antenna is bigger than geodetic antenna.3. When range measurement of two receivers from 5m, to 10m to 15m, the each range error is 0.340m, 0.190m, 0.011m and each standard variation is 0.0973m, 0.0884m, 0.0790m. The range error and standard variation are in inverse proportion to distance between two receivers. 4. L1 Carrier Phase GPS generally needs 5 minutes to fix and during this ambiguity search, the relative range and bearing angle is shown to be various.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.7
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• pp.418-423
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• 2000

The fiber Fabry-Perot interferometric(FFPI) sensor is well known in the field of industrial diagnosis due to its outstanding properties such as tiny size, simple and rugged structure, and easy interrogation. As other fiber interferometric sensors, it also suffers from ambiguous output caused by highly periodic feature in its optical transfer function. In most cases, the ambiguity leads to relatively short dynamic operating range and long processing time during power-on reset, which limits its application to some specific fields requiring very high resolution. In this paper a method based on double sensing scheme was proposed to overcome the above difficulty. By employing a fringe selection auxiliary FFPI sensor the original FFPI sensor can identify its true position on the phase domain. The performance test with 10mm FFPI sensor and a thermocouple temperature sensor for reference shows wide dynamic range 0-900$\ell$ keeping a reasonable resolution of 0.1$\ell$ over the entire range.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.31-37
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• 2010

Based on the analyses of satellite range measurement, the optimal operation for satellite range measurement of KOMPSAT II, which operates in the low-earth orbit, was proposed in this paper. The orbital motion of the satellite was analyzed in viewpoints of radial velocity, acceleration and speed of acceleration. Correspondingly the effects for satellite ranging signal due to satellite motion were analyzed in viewpoints of doppler phenomena, which are doppler frequency, doppler rate and speed of doppler rate. The accuracy and ambiguity probability of the satellite range measurement were quantitatively analyzed under various circumstances. The optimal operation parameters for satellite range measurement were also analyzed based on the analyzed results. The analyzed results in this paper can be utilized in design of small-sized ground station for satellite range measurement.

• Journal of Korean Physical Therapy Science
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• v.9 no.2
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• pp.87-98
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• 2002

The main objective of this study is to evaluate role-related job stressors of physical therapists and to examine the relationship between job stress and organizational effectiveness. A survey was conducted through structured questionnaire for the physical therapists working in Busan area, and data from 175 therapists were utilized in the final analysis. Survey items included general characteristics of the therapists(sex, age, education, marital status, religion, income, etc.), various kinds of job stressors(role conflict, role overload, role ambiguity, physical burden), and organizational effectiveness measured in terms of job satisfaction, organizational commitment and organizational citizenship behavior. Major results are as follows: 1) The level of physical therapists' job stress was found to be in average range, recording 2.65 on 4-point scale. 2) It appeared that main job stressors of physical therapists were role ambiguity and role overload, and this was more apparent in the case of younger, relatively less-educated, unmarried, and lower-grade employees. 3) On the other hand, in the case of relatively more-educated and higher-paid employees, role conflict was comparatively more important job stressor. 4) Regression analysis suggested that, as Job stress increased, job satisfaction and organizational commitment decreased; however, no significant relationship was found between job stress and organizational citizenship behavior. 5) These results imply that, in order to perform effective and efficient personnel administration of physical therapists, adequate job stress management would be very important task for the hospital managers.

• The Korean Society of Law and Medicine
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• v.15 no.2
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• pp.195-223
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• 2014

Nurses are medical care providers most closely associated with the national health. Their works are subdivided and specialized, and it is such a factor making nurse's role more important, and with the appearance of specialized nurses, they have secured a position as an independent medical care provider. As the domain of nurse's service becomes broader, there are more accidents and disputes related to nurses. However, there are not many studies conducted on such problems, and even when medical disputes take place related to nurses, the court does not make consistent judgments as a matter of fact. Besides, as the ambiguity of nurse's range of service and the lack of nursing workforce work as a factor causing nurse's medical malpractice, more legal discussions and studies are required to seek proper solutions to such problems. Thus, as a plan to clarify legal issues likely to occur due to nurse's medical practice, this study classified nurse's work into medical assistance practice and other jobs based on their own independent judgments, and proposed establishing concrete regulations on the range of their work, while reviewing common problems extracted from precedents related nurse's medical malpractice. Moreover, while examining Japanese precedents related to the Act of Medical Service Personnel, Nurses and Midwives, which is the sole act of nurses in Japan, this study reviewed the necessity of revising the present nurse-related regulations in Medical Service Act, or enacting a sole act of nurses.

• The Journal of the Acoustical Society of Korea
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• v.35 no.2
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• pp.158-165
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• 2016

Many researches for improving detection performance in the reverberation environment have been conducted in active sonar systems. Especially the type of active pulse makes an impact on the detection performance in the reverberation environment. Thus, this paper describes the detection performance of PTFM (Pulse Trains of Frequency Modulated waveform), Costas, and Geometric Comb pulses which are known for their outstanding performance against the reverberation. Sea trial data of those pulses was analyzed and it was figured out that the range resolution of PTFM pulse was deteriorated by its sub-pulses. Costas pulse showed performance degradations of the doppler resolution by multipath signals. Geometric Comb pulse showed the best doppler resolution.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.12
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• pp.691-697
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• 2000

A fiberoptic sensor using a low-coherence SLD as a light source has been studied. The sensor system employing an intrinsic fiber Fabry-Peort interferometer as a sensing tip and a fiber Mach-Zehnder interferometer as a processing one, overcomes the ambiguous reading caused by the highly periodic natrue of conventional high-precision interferometric sensors and provides unambiguous identification of the desired phase among several candidates on the transfer function of an interferometric signal. A tentative application to the temperature sensor shows the potential that the fiberoptic sensor has a side-dynamic range of $0-900^{\circ}C$ as well as reasonable resolution higher than $0.1^{\circ}C$ without ambiguity. Due to the inherent property of the optical fiber itself and the intrinsic fiber Fabry-Perot interferometer, the proposed fiberoptic sensor will give obvious benefits when it is applied to harsh environments to monitor some physical parameters such as temperature, strain, pressure and vibration.