• Journal of Magnetics
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• v.20 no.2
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• pp.120-128
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• 2015

Beam-quality of medical linac evaluations vary by diverse factors. Because conventional beam-quality evaluation methods yield fragmentary results, a new beam-evaluation method is suggested, and its feasibility is evaluated. The PDDs (percentage depth doses) of 6 MV (Mega-voltage) and 10 MV photon, R (Range) of a 6 MeV (Mega Electron-voltage) and 9 MeV electron were measured and compared with the conventional evaluation methods, and the improved methods $PDD^{10}{_5}$, $PDD^{20}{_{10}}$, $PDD^{30}{_{20}}$, $PDD^{20}{_5}$, $PDD^{30}{_{10}}$, and $R^{70}{_{50}}$, $R^{50}{_{30}}$, $R^{70}{_{30}}$ as the magnetic field of the bending magnet was changed to +2% to -2%, and the results were compared. The comparison showed that the improved methods exhibit a higher discrimination than the conventional methods in each energy regime. $PDD^{10}{_5}$, $PDD^{30}{_{20}}$, $PDD^{30}{_{10}}$ and $R^{70}{_{50}}$, $R^{50}{_{30}}$ should be applied. These methods exhibit a higher discrimination in each energy regime than conventional beam-quality evaluation methods; therefore, they should be used for beam-quality evaluation according to the magnetic field variation.

• Journal of Korea Game Society
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• v.19 no.2
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• pp.111-122
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• 2019

This study investigated the psychological effects of using a serious game with young learners in the English classroom compared with those of a dictionary application. A tablet PC-based serious game was created for the training of English phoneme discrimination for Korean 6th graders, and its psychological effects were measured using a paper-based survey and face-to-face interviews. The overall results revealed that the serious game had more positive psychological effects on young learners than the dictionary app. These findings provide supporting empirical evidence for using serious games in English classrooms.

• Journal of Information Technology Services
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• v.22 no.1
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• pp.57-74
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• 2023

It has been pointed out as a limitation that the rank of some efficient DMUs(decision making units) cannot be discriminated due to the relativity nature of efficiency measured by DEA(data envelopment analysis), comparing the production structure. Recently, to solve this problem, a DEA-SNA(social network analysis) model that combines SNA techniques with data envelopment analysis has been studied intensively. Several models have been proposed using techniques such as eigenvector centrality, pagerank centrality, and hypertext induced topic selection(HITS) algorithm, but DMUs that cannot be ranked still remain. Moreover, in the process of extracting latent information within the DMU group to build effective network, a problem that violates the basic assumptions of the DEA also arises. This study is meaningful in finding the cause of the limitations by comparing and analyzing the characteristics of the DEA-SNA model proposed so far, and based on this, suggesting the direction and possibility to develop more advanced model. Through the results of this study, it will be enable to further expand the field of research related to DEA.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.1021-1030
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• 2023

We propose an overall procedure for measuring and unfolding fast neutron spectra using a trans-stilbene scintillation detector. Detector characterization was described, including the information on energy calibration, detector resolution, and nonproportionality response. The digital charge comparison method was used for the investigation of neutron-gamma Pulse Shape Discrimination (PSD). A pair of values of 600 ns pulse width and 24 ns delay time was found as the optimized conditions for PSD. A fitting technique was introduced to increase the trans-stilbene Proton Response Function (PRF) by 28% based on comparison of the simulated and experimental electron-equivalent distributions by the Cf-252 source. The detector response matrix was constructed by Monte-Carlo simulation and the spectrum unfolding was implemented using the iterative Bayesian method. The unfolding of simulated and measured spectra of Cf-252 and AmBe neutron sources indicates reliable, stable and no-bias results. The unfolding technique was also validated by the measured cosmic-ray induced neutron flux. Our approach is promising for fast neutron detection and spectroscopy.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1966-1970
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• 1991

The self-mixing type semiconductor laser Doppler velocimeter(SM-LDV) is applied to measure two simultaneously moving targets with different velocities in the same direction as a prototype target for multiscatterers. The measured beat waveform is found to be a composite wave of each beat waveform measured fran each of only moving target. In the composite waveform, each one-cycle wave has a feature of the sawtooth wave. This fact shows a possibility to discriminate the flow direction of fluid containing multiscatterers with distributed velocities by cooperating an improved version of the direction discrimination circuit already devised by the authors.

• The Journal of Korean Physical Therapy
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• v.16 no.4
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• pp.218-225
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• 2004

OBJECTIVES: This study was performed to find out static two-point discrimination (TPD) in fingertips. METHODS: This was a cross-section, measure study of static two-point discrimination involving healthy young adults. Measure was completed by 48 college students in Andong Science College from June 1 to 12, 2004. The minimal distance at which two-points could be discriminated was measured from thumb to little finger. RESULTS: For dermatomal regions of the fingertip, mean values ranged from 3.3mm to 4.9mm (thumb 3.6mm, index finger 3.3mm, middle finger 3.8mm, ring finger 4.2mm, and little finger 4.7mm in the left hand; thumb 3.7mm, index 3.5mm, middle 4.0mm, ring 4.3mm, and little 4.9mm in the right hand). A significant difference in discrimination ability was found between men and women, 3.5mm for women showed a greater sensitivity than 4.1mm for men in the left middle fingertip(p=0.0109), also 3.9mm for women showed a greater accuracy than 4.5mm for men in the left ring fingertip(p=0.0388). In the right index fingertip, women (3.1mm) have a narrow distance than men (3.6mm)(p=0.0329). The minimal distance of TPD was found a significant difference between 20 and 30 years in age. 4mm for 30 years showed a greater distance than 3.5mm for 20 years in the left thumb fingertip(p=0.0354), also, 3.8mm for 30 years showed a greater distance than 3.2mm for 20 years in the left index fingertip(p=0.0174), and 4.3mm for 30 years showed a greater distance than 3.7mm for 20 years in the left middle fingertip(p=0.0444). In the right index fingertip, 20 years (3.2mm) had also a narrow distance than 30 years (4.1mm)(p=0.0020), 20 years (3.9mm) showed a narrow distance than 30 years (4.6mm) in the right middle fingertip(p=0.0124), and 20 years (4.1mm) showed a greater sensitivity than 30 years (5.0mm) in the right ring fingertip(p=0.0070). CONCLUSIONS: Our results suggest that distance of TPD in the both index fingertips for 20 years women was significantly narrowed.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.29-33
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• 2020

The objective of this study was to develop a fast and accurate method of variety discrimination and geographical discrimination origin of Korean angelica (Korean variety, Angelica gigas Nakai) by using TDU-GC/MS. Two peaks of decursin and decursinol, which are coumarin derivatives were identified in the range of Total Ion Chromatogram (TIC) RT 26.9-27.2 of the Korean angelica by GC/MS analysis at the time of condensation in a refrigerated condensation system after thermal desorption of sample extracts. In case of Chinese angelica (Chinese variety), ligustilide peak was detected at the RT 17.2. In order to investigate the difference of volatile components according to the geographical origin of Korean variety, the mass spectra were measured by TDU-GC/MS at the range of m/z 40-400 amu. The TIC of domestic cultivation and Chinese cultivation of the Korean variety, Angelica gigas Nakai showed the same tendency as a whole. However, in partial scans of TIC, two peaks detected at 15.54 and 16.05 of RT showed different peak patterns between Korean angelica (Korean variety) cultivated in Korea and in China. The ratio of Peak A (RT 15.54) and B (RT 16.05) was 0.0-0.2 for domestic cultivation and 0.5-2.8 for Chinese cultivation, confirming the possibility of discriminating origin by comparing the TIC peak pattern of TDU-GC/MS.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.2
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• pp.99-104
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• 2019

Recently, modern people are increasing the incidence of various musculoskeletal diseases due to wrong posture. Prevention is possible through proper posture habit, but it is not easy to recognize posture by oneself. Various studies have been conducted to monitor persistent posture in daily life, but most studies using constrained measurement methods and high-cost measurement equipment are not suitable for daily life. In this paper, we implemented a posture discrimination system using a FSR sensor array that can induce posture correction spontaneously through sitting posture monitoring in daily life. The implemented system is designed as a cushion type so it is easy to apply to existing chair. In addition, it can identify five most common postures in everyday life, and can monitor real-time through Android-based smart-phone monitoring application. For the performance evaluation of the implemented system, each posture was measured 50 times repeatedly. As a result, 97.6% accuracy was confirmed.

• Journal of the Korean Society for Nondestructive Testing
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• v.14 no.2
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• pp.112-121
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• 1994

This paper discusses the feasibility of ultrasonic C-scan technique for nondestructive evaluation of spot weld quality. Ultrasonic evaluation for spot weld quality was performed by immersion method with the mechanical and the electronic scanning of point-focussed ultrasonic beam(25 MHz). For the sake of the approach to the quantitative measurement of nugget diameter and the discrimination of the corona bond from nugget, preliminary infinitesimal gap experiment by newton ring is tried in order to set up the optimum ultrasonic test condition. Ultrasonic image data obtained were confirmed and compared by optical microscope and SAM(Scanning Acoustic Microscope) observation of the spot-weld cross section. The results show that the nugget diameter can be measured with the accuracy of 1.0mm, and voids included in nugget can be detected to $10{\mu}m$ extent with simplicity and accuracy. Finally, it was found that it is necessary to make a profound study of definite discrimination of corona bond from nugget and the approach of quantitative evaluation of nugget diameter by utilizing the various image processing techniques.

• Archives of Plastic Surgery
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• v.39 no.6
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• pp.637-642
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• 2012

Background Fingertip injuries involving subtotal or total loss of the digital pulp are common types of hand injuries and require reconstruction that is able to provide stable padding and sensory recovery. There are various techniques used for reconstruction of fingertip injuries, but the most effective method is functionally and aesthetically controversial. Despite some disadvantages, cross-finger pulp flap is a relatively simple procedure without significant complications or requiring special techniques. Methods This study included 90 patients with fingertip defects who underwent cross-finger pulp flap between September 1998 and March 2010. In 69 cases, neurorrhaphy was performed between the pulp branch from the proper digital nerve and the recipient's sensory nerve for good sensibility of the injured fingertip. In order to evaluate the outcome of our surgical method, we observed two-point discrimination in the early (3 months) and late (12 to 40 months) postoperative periods. Results Most of the cases had cosmetically and functionally acceptable outcomes. The average defect size was $1.7{\times}1.5$ cm. Sensory return began 3 months after flap application. The two-point discrimination was measured at 4.6 mm (range, 3 to 6 mm) in our method and 7.2 mm (range, 4 to 9 mm) in non-innervated cross-finger pulp flaps. Conclusions The innervated cross-finger pulp flap is a safe and reliable procedure for lateral oblique, volar oblique, and transverse fingertip amputations. Our procedure is simple to perform under local anesthesia, and is able to provide both mechanical stability and sensory recovery. We recommend this method for reconstruction of fingertip injuries.