• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.245-254
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• 2006

While orofacial pain or various dental factors are generally considered as the primary cause of unilateral chewing tendency, there exist several studies indicating that dental factors did not affect the preferred chewing side. The aim of this study was to examine difference of occlusal scheme between the subjects with and without chewing side preference. The difference between the chewing and non-chewing sides in the unilateral chewing group was investigated as well. Computerized, T-Scan II system was used for occlusal analysis. 20 subjects for the unilateral chewing group (mean age of $25.25{\pm}2.84$ years) and 20 subjects for the bilateral chewing group (mean age of $27.00{\pm}5.07$ years) were selected by a questionnaire on presence or absence of chewing side preference and those with occlusal problem or pain and/or dysfunction of jaw were excluded. T-Scan recordings were obtained during maximum intercuspation and excursion movement. The number of contact points, relative occlusal force ratio between right and left sides, tooth sliding area and elapsed time throughout the maximum intercuspation were calculated. Elapsed time for excursion was also investigated. The results of this study shows that the unilateral chewing group had the smaller average tooth contact areas compared with those of the bilateral group (p<0.005). In the unilateral chewing group, the contact areas of non-chewing side are smaller than those of chewing side (p<0.005). The contact areas on their preferred sides were not significantly different with those of right or left side of the subjects without chewing side preference. There was no significant difference in the elapsed time during maximum intercuspation and lateral excursion, the sliding areas and relative of right-to-left occlusal force ratio between the two groups. From the results of this study, it is likely that individuals prefer chewing on the side with more contact areas for efficient chewing.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.119-126
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• 2009

This paper describes the non-stringed guitar composed of laser strings, frets, sound synthesis algorithm and a processor. The laser strings that can depict stroke and playing arpeggios comprise laser modules and photo diodes. Frets are implemented by voltage divider. The guitar body does not need to implement physically because commuted waveguide synthesis is used. The proposed frets enable; players to represent all of chords by the chord glove as well as guitar solo. Sliding, hammering-on and pulling-off sounds are synthesized by using parameters from the voltage divider. Because the pitch shifting corresponds to the time-varying propagation speed in the digital waveguide model, the proposed model can synthesize vibrato as well. After transformation of signals from the laser strings and frets into parameters for synthesis algorithm, the digital signal processor, TMS320F2812, performs the real-time synthesis algorithm and communicates with the DAC. The demonstration movieclip available via the Internet shows one to play a song, 'Arirang', synthesized by proposed algorithm and interfaces in real-time. Consequently, we can conclude that the proposed synthesis algorithm is efficient in guitar solo and there is no problem to play the non-stringed guitar in real-time.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.145-159
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• 2004

A mathematical model and its computer solution program were proposed to analyze the motion of contact lenses which are being subject to lid-blinking. The equation was derived by incorporating an acceleration induced lid's force exerting on the contact lens, the viscous damping resistance in the tear layer beneath the lens and the sliding frictional force between the lid and the contact lens surface into the formulation of differential equation describing the vibration. The model predicts the time-dependent displacement from the equilibrium postion during/after the blinking. During the blinking, as the time for the completion of one cycle of blinking decreases the off-the-equilibrium displacement of contact lens increases while the decrease of diameter in the contact cause the opposite effect. It is found that lid pressure exerting on the lens cause an insignificant lens displacement from the equilibrium position. After blinking the frequency of damped oscillation of contact lens decreases as the diameter of lens increases, due to the incresed surface while the reduced blinking time does not cause a significant frequency change. This is because that driving force for the contact lens movement posterior to blinking is the capillary-induced force not the lid force.

• Magazine of the Korean Society of Agricultural Engineers
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• v.28 no.3
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• pp.79-88
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• 1986

Drought occurs most frequently and severely around transplanting season of the rice plants in Korea. Shortage of water due to drought for the paddy fields often delays transplanting, and less often the rice plants are subjected to water stress after delayed transplanting. The present study aimed at quantification of the rice crop loss due to delayed transplanting, different inten3ity of water stress, and the combined effect of delay in transplanting followed by water stress for better use of limited water for irrigation under drought. The rice variety Chucheong, a japonica, and Nampung, an indica x japonica, were grown, transplanted to 1/200 a plastic pots, and subjected to different timing of transplanting and degree of water stress under a rainfall autosersing, sliding clear plastic roof facility with completely randomized arrangement of 5 replications. The results obtained are summarized as follows: 1.Twelve days or 22 days delay in transplanting without water stress reduced rice yield by 25% and 43% in the japonica variety, and by 15% and 60% in the indica x japonica variety. 2.The 10 days or 20 days water stress developed without irrigation after drainage in the rice plants transplanted at proper time lowered the water potential at the paddy soil 10cm deep to -4 bar, and -12 bar and caused rice yield reduction by 14%, and 45% in the japonica variety and by 8%, and 50% in the indica X japonica variety. 3.The 12 days delay in transplanting and 10 days or 20 days water stress reduced rice yield by 39% and 59% in the japonica variety, and by 38% and 52% in the indica x japonica variety. The 22 days delay in transplanting plus 10 days water stress caused yield reduction by 76%, i.e. meaningless yield, in both varieties. 4.The intermittent irrigation just to wet the soil body for 10 days after 10 days water stress without irrigation increased rece yield by 12 to 16% compared to the rice plants water stessed without irrigation continuously for 20 days in both varieties respectively. 5.The above results suggest strongly 1) to transplant the rice plants at proper .time even with some water stress rather than delay for sufficient water from later rainfall, and 2) to distribute insufficient irrigation water to broader area of transplanted rice with limited irrigation for better use of limited irrigation water. A greater sensitivity of japonica variety to a moderate water stress than the indica X japonica variety during initial rooting and tillering stage was noticed. To cope with frequent drought in rice culture, firstly the lasting time of transplanting without yield reduction should be clarified by region and variety, and secondly a scheme of rational distribution of limited water should be developed by region with better knowledge on the varietal distribution of limited water should be developed by region with better knowledge on the varietal responses to varying intensity of water stress.

• Journal of KIISE:Databases
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• v.37 no.4
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• pp.177-184
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• 2010

In these day, many data including sensor, delivery, credit and stock data are generated continuously in massive quantity. It is difficult to learn from these data because they are large in volume and changing fast in their concepts. To handle these problems, learning methods based in sliding window methods over time have been used. But these approaches have a problem of rebuilding models every time new data arrive, which requires a lot of time and cost. Therefore we need very simple incremental learning methods. Bayesian method is an example of these methods but it has a disadvantage which it requries the prior knowledge(probabiltiy) of data. In this study, we propose a learning method based on attribute values. In the proposed method, even though we don't know the prior knowledge(probability) of data, we can apply our new method to data. The main concept of this method is that each attribute value is regarded as an expert learner, summing up the expert learners lead to better results. Experimental results show our learning method learns from data very fast and performs well when compared to current learning methods(decision tree and bayesian).

• Journal of the Korean GEO-environmental Society
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• v.16 no.4
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• pp.5-12
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• 2015

Civil engineers have taken the numerous slope monitoring data for an engineering project subjected to hazard potential of slide. However, the topics on how to deal with and draw out proper information from the data related to the slope behavior have not been widely discussed. Recently, several researchers had installed the real-time monitoring system to cope with slope failure; however they are mainly focused on the hardware system installation. Therefore, this study tries to show how the measured data could be grouped and connected each other. The basic idea of analyzing method studied in this paper came from the clustering, which is the part of data mining analysis. Therefore, at the base of classification of time series data, the authors suggest three mathematical data analyzing methods; Average Index of different displacement ($AD_{i,j}$), Difference of average relative displacement ($\overline{RD}_{i,j}$) and Coordinate system of average and relative displacement ($\overline{RD}$, AD). These analyzing methods are based on the statistical method and failure mechanism of slope. Therefore they showed clustering relationships of the similar parts of the slope which makes the same sliding mechanism.

• Fibers and Polymers
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• v.7 no.4
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• pp.389-397
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• 2006

The beneficial effects of graduated compression stockings (GCS) in prophylaxis and treatment of venous disorders of human lower extremity have been recognized. However, their pressure functional performances are variable and unstable in practical applications, and the exact mechanisms of action remain controversial. Direct surface pressure measurements and indirect material properties testing are not enough for fully understanding the interaction between stocking and leg. A three dimensional (3D) biomechanical mathematical model for numerically simulating the interaction between leg and GCS in dynamic wear was developed based on the actual geometry of the female leg obtained from 3D reconstruction of MR images and the real size and mechanical properties of the compression stocking prototype. The biomechanical solid leg model consists of bones and soft tissues, and an orthotropic shell model is built for the stocking hose. The dynamic putting-on process is simulated by defining the contact of finite relative sliding between the two objects. The surface pressure magnitude and distribution along the different height levels of the leg and stress profiles of stockings were simulated. As well, their dynamic alterations with time processing were quantitatively analyzed. Through validation, the simulated results showed a reasonable agreement with the experimental measurements, and the simulated pressure gradient distribution from the ankle to the thigh (100:67:30) accorded with the advised criterion by the European committee for standardization. The developed model can be used to predict and visualize the dynamic pressure and stress performances exerted by compression stocking in wear, and to optimize the material mechanical properties in stocking design, thus, helping us understand mechanisms of compression action and improving medical functions of GCS.

• Applied Microscopy
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• v.10 no.1_2
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• pp.7-17
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• 1980

Electron microscope radioautography introduced by Liquier-Milward (1956) is now used routinely in many laboratories. Most of the technical difficulties in specimen preparation have been overcome. This method is modified from loop method for improvement of EM radioautographic techniques. The advantages of this method are: 1. the use of single specimens on small corks and of a large wire loop, allows the experimenter to avoid the blemishes in the membrane; 2. the surfactant dioctyl sodium sulphosuccinate is added to diluted ILford L4, thus greatly prolonging the period of time over which good emulsion layers can be made; 3. corks can be handled in perspex holder which allows about 20 specimens to be developed simultaneously. The steps of the method comprise: 1. Cut ribbons of ultrathin sections of silver interference colour 2. Pick them up on formvar-coated 200 mesh grids 3. Prestaining of tissues 4. Coat the specimens with a thin layer of carbon by evaporation (30-60A) 5. Mount the specimens on corks (about 1cm apical diameter) using double-sided scotch tape 6. Emulsion coating; a. Take a 250m1 beaker, place it on the pan of a sliding weight balance and weigh it. Add 10 grams extra to the beam. Add pieces of ILford L4 emulsion to the beaker until the balance is swinging freely. Add the 20ml of distilled water that was previously measured out. b. Surfactant dioctyl sodium sulphosuccinate is added to diluted ILford L4. 7. Prepare a series of membranes of gelled emulsion with the wire loop and apply one to each cork-borne specimen. 8. Put the specimens away to expose by pushing the corks into short length of PVC tubing, each tube having a small hole in the side 9. Place the tubes in small boxes together with silica gel. 10. Exposure 11. Developer - Kodak Microdol X for 3 minutes 12. Fixer - A perspex holder can be manufactured which allows 20 specimens to be developed simultaneously. 12. Fixer - 30% sodium thiosulfate for 10 minutes 13. Examination with Siemens Elmiskop 1A electron microscope

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.157-157
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• 2017

To minimize the damage by wild birds and acquire the benefits such as protection against weeds and maintenance of water content in soil, the mulching black color vinyl after seeding should be carried out. Non-contact and non-destructive methods that can continuously determine the locations are necessary. In this study, a crop position detection method was studied that uses infrared thermal image sensor to determine the cotyledon position under vinyl mulch. The moving system for acquiring image arrays has been developed for continuously detecting crop locations under plastic mulching on the field. A sliding mechanical device was developed to move the sensor, which were arranged in the form of a linear array, perpendicular to the array using a micro-controller integrated with a stepping motor. The experiments were conducted while moving 4.00 cm/s speed of the IR sensor by the rotational speed of the stepping motor based on a digital pulse width modulation signal from the micro-controller. The acquired images were calibrated with the spatial image correlation. The collected data were processed using moving averaging on interpolation to determine the frame where the variance was the smallest in resolution units of 1.02 cm. Non-linear integral interpolation was one of method for analyzing the frequency using the normalization image and then arbitrarily increasing the limited data value of $16{\times}4pixels$ in one frame. It was a method to relatively reduce the size of overlapping pixels by arbitrarily increasing the limited data value. The splitted frames into 0.1 units instead of 1 pixel can propose more than 10 times more accurate and original method than the existing correction method. The non-integral calibration method was conducted by applying the subdivision method to the pixels to find the optimal correction resolution based on the first reversed frequency. In order to find a correct resolution, the expected location of the first crop was indicated on near pixel 4 in the inversion frequency. For the most optimized resolution, the pixel was divided by 0.4 pixel instead of one pixel to find out where the lowest frequency exists.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.174-180
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• 2006

The wheel slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional braking control systems. In order to achieve the superior braking performance through the wheel slip control, real-time information such as the tire braking force at each wheel is required. In addition, the optimal target slip values need to be determined depending on the braking objectives such as minimum braking distance, stability enhancement, etc. In this paper, a wheel slip control system is developed for maintaining the vehicle stability based on the braking monitor, wheel slip controller and optimal target slip assignment algorithm. The braking monitor estimates the tire braking force, lateral tire force and brake disk-pad friction coefficient utilizing the extended Kalman filter. The wheel slip controller is designed based on the sliding mode control method. The target slip assignment algorithm is proposed to maintain the vehicle stability based on the direct yaw moment controller and fuzzy logic. The performance of the proposed wheel slip control system is verified in simulations and demonstrates the effectiveness of the wheel slip control in various road conditions.