• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.114-116
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• 2006

This paper is to propose the palm print recognition system using wavelet transform. The palm print is frequently used as the material for the biometric recognition system such as the finger print, iris, face, etc. Since the palm print has lots of properties which include principle line, wrinkles, ridge and so forth, the ways of the implementation of the system are various. In this paper, at first, the palm print image is acquired and then some level of wavelet transform is performed. The coefficients become to be some blocks size of M by N after divided into the horizontal, vertical, diagonal components each level. The mean values, which are calculated with values of each block, are used as the feature vector. To compare between the stored template and the acquired vectors, we adopt the PNN (Probability Neural Network) method.

• Restorative Dentistry and Endodontics
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• v.7 no.1
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• pp.71-75
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• 1981

Five different labelled composite resin, Hypol (Korea), Glass-Ionomer (Japan), Simulate (U.S.A.), Durafil (U.S.A.) and Microfil (U.S.A.) were collected to employ for this experimental study. The purpose of the study is to determine the effect of finger pressure technic and traditional filling by means of plastic instruments on porosity formation in composite materials. Each material with pressure and non-pressure cases were carefully examined under electron microscope. Following were the results obtained through the study. 1. Pressured cases showed smaller number of porosity and the size of porosity was significantly smaller than non-pressured cases in each mateial. 2. Glass-Ionomer with pressure cases were seen as tube-like appearance because of pressured small porosities communicate in a certain direction. 3. Durafil cases both pressured and non pressured, appeared the least porosity formation. among the materiats. 4. Border line between the outmost periphery of the porosity and matrix of the resin in both pressured or non-pressured eases were found characteristically clear in Mierofil cases.

• Korean Membrane Journal
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• v.9 no.1
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• pp.1-11
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• 2007

To prepare chemically stable asymmetric microporous membranes with a hydrophilic surface, which would be expected to have better antifouling properties, poly(vinylidene fluoride) (PVDF) blend membranes were prepared by the phase inversion process. PVDF mixture solutions in N-methylpyrrolidone (NMP) blended with several polar potential ionic polymers such as polyacrylonitrile (PAN), poly(methylmethacrylate) (PMMA) and poly(N-isopropylacrylamide) (NIPAM) were used for the formation of the PVDF blend membranes. They were then characterized with several analytical methods such as FESEM, FTIR, contact angle measurement, pore size distribution and permeability measurement. Regardless of different polar polymers blended, they all showed a finger-like structure with more hydrophilic surface than the pristine PVDF membrane. For all the PVDF blend membrane, due to the polar potential ionic polymers used, the flux of those was improved. Especially the PVDF blend membrane with NIPAM showed the highest flux among the membranes prepared. Also antifouling property of the PVDF membrane was improved by the use of the polar polymers.

• Clinical Pain
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• v.20 no.2
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• pp.70-73
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• 2021

A minimally invasive procedure refers to a procedure that minimizes tissue damage due to incision. By limiting the size of the incision, it can be expected to reduce the time taken for wound healing, reduce pain, and reduce the risk of infection. Recently, studies have been attempted to dissect the structures of the neuromusculoskeletal system using ultrasound-guided minimally invasive technique. Among those, dissecting thread may be utilized in several musculoskeletal diseases, including carpal tunnel syndrome, cubital tunnel syndrome, trigger finger, and selective crural fasciectomy. In this brief review, the use of dissecting thread in treating neuromusculoskeletal diseases are described.

• Journal of Preventive Medicine and Public Health
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• v.30 no.3 s.58
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• pp.577-584
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• 1997

Validation and Standardization of neurobehavioral instrument in Korean occupational setting has not been studied ever. This study tried to validate the newly developed computerized psychomotor tests, Neurobehavioral Tests for Occupational Screening (NTOS). Male patients with Parkinson's disease(n=12) and male workers who never exposed to occupational neurotoxic materials and didn't have neurologic disease(n=21), performed some tests from NTOS; simple reaction time, choice reaction time(2 choice), and finger tapping(both hands). In simple analysis, difference between patient group and worker group was significantly great. Adjusted for age and education years, simple reaction time and finger tapping(both hand) were statistically significantly different between two groups(p<.05). Choice reaction time was also different(p<.1) but error frequency of choice reaction time test was not. Generally, this results showed NTOS could detect impairment of psychomotor function. But insensitive results of choice reaction time was partly due to small sample size and confounding variables and so required future study and refinement at improvement of NTOS.

• Journal of the Ergonomics Society of Korea
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• v.33 no.5
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• pp.395-405
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• 2014

Objective: The aim of this study is to investigate 1) somatotopic arrangement of the second and third fingers in SI area 2) difference of neural activation in the SI area produced by stimulation with different frequencies 3) correlation between the intensity of tactile perception by different stimulus intensity and the level of brain activation measurable by means of fMRI. Background: Somatosensory cortex can obtain the information of environmental stimuli about "where" (e.g., on the left palm), "what" (e.g., a book or a dog), and "how" (e.g., scrub gently or scrub roughly) to organism. However, compared to visual sense, the neural mechanism underlying the processing of specific electrotactile stimulus is still unknown. Method: 10 right-handed subjects participated in this study. Non-painful electrotactile stimuli were delivered to two different finger tips of right hand. Functional brain images were collected from 3.0T MRI using the single-shot EPI method. The scanning parameters were as follows: TR and TE were 3000, 35ms, respectively, flip angle 60, FOV $24{\times}24cm$, matrix size $64{\times}64$, slice thickness 4mm (no gap). SPM5 was used to analyze the fMRI data. Results: Significant activations produced by the stimulation were found in the SI, SII, the subcentral gyrus, the precentral gyrus, and the insula. In all participants, statistically significant activation was observed in the contralateral SI area and the bilateral SII areas by the stimulation on the fingers but ipsilaterally dominant. The SI area representing the second finger generally located in the more lateral and inferior side than that of the third finger across all the subjects. But no difference in brain area was found for the stimulation of the fingers by different frequencies. And two typical patterns were observed on the relationship between the perceived psychological intensity and the amount of voxels in the primary sensory cortex during the stimulation. Conclusion: It was possible to discriminate the representation sites in the SI by electrotactile stimulation of digit2 and digit3. But we could not find the differences of the brain areas according to different stimulation frequencies from 3 to 300Hz. Application: The results of the study can provide a deeper understanding of somatosensory cortex and offer the information for tactile display for blinds.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1029-1032
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• 2002

This paper describes a design of a tactile sensor, which can measure three components force and temperature due to thermal conductive. The bio-mimetic tactile sensor, alternative to human's finger, is comprised of four micro force sensors and four thermal sensors, and its size being 10mm$\times$10mm. Each micro force sensor has a square membrane, and its force range is 0.1N - 5N in the three-axis directions. On the other hand, the thermal sensor for temperature measurement has a heater and four temperature sensor elements. The thermal sensor is designed to keep the temperature. $36.5^{\circ}C$, constant, like human skin, and measure the temperature $0^{\circ}C$ to $50^{\circ}C$. The MEMS technology is applied to fabricate the sensing element of the tactile sensor.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.407-429
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• 2004

As documents in webs are increasing explosively due to the rapid development of electronic documents, an efficient system classifying documents automatically is required. In this study, a new document classification method, which is called Document Finger Print Method, is suggested to classify web documents automatically and efficiently. The performance of the suggested method is evaluated alone with other existing methods such as key words based method, weighted key words based method, neural networks, and decision trees. An experiment is designed with 10 documents categories and 59 randomly selected words. The result shows that the suggested algorithm has a superior classifying performance compared to other methods. The most important advantage of this method is that the suggested method works well without the size limits of the number of words in documents.

• Nuclear Engineering and Technology
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• v.33 no.2
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• pp.192-200
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• 2001

Hydride blisters were formed on the outer surface of Zr-2.5Nb pressure tube by a non- uniform steady thermal diffusion process. A thermal gradient was applied to the pressure tube with a heat bath kept at a temperature of 415$^{\circ}C$ and an aluminum cold finger cooled with flowing water of 15$^{\circ}C$. Optical microscopy and tree-dimensional laser profilometry were used to characterize the hydride blisters with different hydrogen concentrations and thermal diffusion time. Hydride blisters were expected to start at a hydrogen concentration of 30 - 70 ppm and a thermal diffusion time of 4 - 6$\times$10$^{5}$ sec. The hydride blister size increases with higher hydrogen concentrations and longer thermal diffusion time . Some of the samples revealed cracks on the hydride blisters. The ratio of hydride blister depth to height was estimated as approximately 8: 1.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.39-48
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• 2016

In this paper, we propose thermal resistance compact model of FinFET structure that has hexagon shaped source/drain. The heating effect and thermal properties were increased by reduced size of the device, and thermal resistance is an important factor to analyze the effect and the properties. The heat source and each contact that is moved heat out were set up in transistor, and domain is divided by the heat source and the four parts of contacts : source, drain, gate, substrate. Each contact thermal resistance model is subdivided as a easily interpretable structure by analyzing the temperature and heat flow of the TCAD simulation results. The domains are modeled based on an integration or conformal mapping method through the structure parameters according to its structure. First modeled by analyzing the thermal resistance to a single fin, and applying the change in the parameter of the channel increases to improve the accuracy of the thermal resistance model of the multi-fin/ finger. The proposed thermal resistance model was compared to the thermal resistance by analyzing results of the 3D Technology CAD simulations, and the proposed total thermal resistance model has an error of 3 % less in single and multi-finl. The proposed thermal resistance model can predict the thermal resistance due to the increase of the fin / finger, and the circuit characteristics can be improved by calculating the self-heating effect and thermal characterization.