• Cartoon and Animation Studies
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• s.14
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• pp.37-51
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• 2008

The computer has become an indispensable tool for animation works. However if you don't understand the characteristics of the computer and its software, you might not have the result satisfying your efforts. The incorrect understanding of image format sometimes causes it. Habitually image formats are selected usually for most of works but there is a distinct difference among those image formats while the efficient usages of them are different from each other. For your more efficient work therefore, you need to identify the characteristics of various kinds of image format used mostly for animation works. First I took a look at the theories of the lossy compression and lossless compression, which are two types of data compression widely used in the whole parts of computer world and the difference between bitmap method and vector method, which are respectably different in terms of the way of expressing images and finally the 24 bit true color and 8 bits alpha channel. Based on those characteristics, I have analyzed the functional difference among image formats used between various types of animation works such as 2D, 3D, composing and editing and also the benefits and weakness of them. Additionally I've proved it is wrong that the JPEG files consume a small space in computer work. In conclusion, I suggest the TIF format as the most efficient format for whatever it is editing, composing, 3D and 2D in considering capacity, function and image quality and also I'd like to recommend PSD format which has compatibility and excellent function, since the Adobe educational programs are used a lot for the school education. I hope this treatise to contribute to your right choice of image format in school education and practical works.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.121-133
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• 2016

It was required to evaluate ecological restorations in a comprehensive way in order to systematically manage conservation areas such as DMZ and national parks in South Korea. In this research we developed a new approach to evaluating ecological restorations with more various indexes than vegetation covering-related indexes. By analyzing damaged areas in the vicinity of DMZ, major damaged types were identified as six classes: landform modification, surface loss, soil pollution, soil physio-chemical modification, vegetation decline and vegetation damaged. From literature review, 39 indexes were selected and were grouped into four divisions: soil property, vegetation growth & structure, habitat property and landscape structure & functions. By conducting a survey with the selected indexes targeting relevant experts, data on relative importance among the divisions and indexes by damaged type were collected. As a result, it was found that the orders and values of weighted values of the divisions were different by damaged type: for example, soil property (0.402), vegetation growth & structure (0.209), habitat property (0.225), landscape structure & function (0.163) for "landform modification"; but soil property (0.171), vegetation growth & structure (0.401), habitat property (0.270), landscape structure & function (0.158) for "vegetation decline". Similarly, evaluation indexes showed different orders and values of relative importance, easiness in field measurement and representativeness for the division by damaged type, and the values were used for calculating importance factor for each index. In the evaluation table, score1 and score2 were made by the importance factors of indexes multiplied by distribution values which present grades and by the weighted values of divisions. In conclusion, while dealing with the damaged type was considered significant for evaluating and managing restorations, further tests on this table with a range of cases were needed to improve its quality.

• Applied Microscopy
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• v.22 no.2
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• pp.15-29
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• 1992

The gallbladder is known to have the function of the storage and the concentration of the bile produced by the liver. This function is carried out by the removal of water and inorganic electrolytes. Extrahepatic cholestasis or the impairment of excretion of the bile leads to the distension and loss of the function of the gallbladder. The purpose of this study was to examine the ultrastructural characteristics of the normal gallbladder epithelial cells, and their structural changes induced by the ligation of common bile duct of the rabbit. Common bile duct ligation was performed under ether anesthesia. The rabbits were sacrificed on the 1st, 3rd, 5th, 7th and 14th day, respectively after operations. The tissue blocks of the gallbladder were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde prior to fixation in 1% osmium tetroxide, and embedded in the araldite mixture, and observed with JEM 100 CX-II electron microscope. The results were as follows: 1. The normal gallbladder epithelium of adult rabbit demonstrated two cell types, the ordinary epthelial cell and the dark cell. The dark cells have electron dense cytoplasm, and were found much infrequently, whereas ordinary epthelial cells were found quite numerous. 2. The ordinary epthelial cells of normal gallbladder were provided with the regular microvilli at the free surface and the images of pinocytotic activities in the apical cytoplasm, and exhibit highly convoluted lateral surfaces with elaborated microfolds. These figures of the cells suggest that they are resorptive in functional activity. 3. In the early stages (1st, 3rd, 5th day groups) following the ligation, the apical cytoplasm of some cells is protruding from the free surface and lost their microvilli. Numerous mucous granules filled in the apical and supranuclear cytoplasm compactly. 4. In the late stages (7th, 14th day groups) following the ligation, many light cells containing mumerous mucous granules are seen, between the ordinary epthelial cells. Mucous granules are fused each other, and are discharged into the lumen from the apical cytoplasm. The lateral membranes are straight or undulating without any interdigitations. From the above results, it was concluded that in the cholestasis induced by the common bile duct ligation, there is a tendency for the mucosal epithelium of the rabbit gallbladder to have secretory rather than an absorptive function.

• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.133-142
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• 2007

As the environmental pollution caused by excessive uses of chemical fertilizers and pesticides is aggravated, organic farming using pasture and livestock manure is gaining an increased necessity. The application rate of the organic farming materials to the field is determined as a function of crops and soil types, weather and cultivation surroundings. When livestock manure is used for organic farming materials, the volatilization of ammonia from field-spread animal manure is a major source of atmospheric pollution and leads to a significant reduction in the fertilizer value of the manure. Therefore, an ammonia emission model should be presented to reduce the ammonia emission and to know appropriate application rate of manure. In this study, the ammonia emission rate from field-applied pig manure is predicted using an artificial neural network (ANN) method, where the Michaelis-Menten equation is employed for the ammonia emission rate model. Two model parameters (total loss of ammonia emission rate and time to reach the half of the total emission rate) of the model are predicted using a feedforward-backpropagation ANN on the basis of the ALFAM (Ammonia Loss from Field-applied Animal Manure) database in Europe. The relative importance among 15 input variables influencing ammonia loss is identified using the weight partitioning method. As a result, the ammonia emission is influenced mush by the weather and the manure state.

• The Journal of the Acoustical Society of Korea
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• v.39 no.3
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• pp.151-162
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• 2020

This paper presents an acoustic inversion method for estimating the bubble size distribution. The estimation error of the attenuation coefficient represented by a Fredholm integral equation of the first kind is defined as an objective function, and an optimal solution is found by applying the Levenberg-Marquardt (LM) method. In order to validate the effectiveness of the inversion method, numerical simulations using two types of bubble distribution are performed. In addition, a series of experiments are carried out in a water tank (1.0 m × 0.54 m × 0.6 m), using bubbles generated by three different generators. Images of the distributed bubbles are obtained by a high-speed camera, and the insertion losses of the bubble layer are measured using a source and a hydrophone. The image is post-processed to glance a distribution characteristics of each bubble generator. Finally, the size distribution of bubbles is estimated by applying the inversion method to the measured insertion loss. From the inversion results, it was observed that the number of bubbles increases exponentially as the bubble size decreases, and then increases again after the local peak at 70 ㎛ - 120 ㎛.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.2
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• pp.97-109
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• 2010

Purpose : This study was designed to evaluate the influence of implant abutment materials on detorque value and screw joint stability before and after dynamic fatigue test. Materials & Methods : The external hexagonal fixture and three different groups of abutment (titanium abutments, zirconia abutments, and UCLA abutments) were used. The detorque value before loading and after loading (cyclic loading up to $10^5$ cycles) of the abutment screw were measured. Result : 1. There was no significant difference in detorque value before loading among the each group. 2. There was no significant difference in detorque value after loading among the each group. 3. Detorque values before and after cyclic loading in each group were not significantly different. 4. There was no significant difference in loss percentage of removal torque before loading among the each group. 5. There was no significant difference in loss percentage of removal torque after loading among the each group. 6. There was no significant difference in loss percentage of removal torque according to loading among the each group. Conclusion : Short term screw loosening of three types of abutment was not significantly different. When bite force was applied, there was no significant difference in screw loosening between before loading and after loading.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.3
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• pp.278-285
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• 2013

In this paper, a 100~110 GHz LNA and A coupler using standard 65 n CMOS process is presented. The LNA consists of three common source FET stages. A few layout types are considered to get high gain characteristic of unit common source cell. Also, optimized performance to achieve low noise characteristic and enough gain. Coupler is composed of broadside coupler using multimetal in CMOS fabrication. In the coupler, the metal strip to meet density rule is used, and the coupler is designed with consideration of the metal strip to function properly. Gain of fabricated LNA is 5.64 dB at 100 GHz and 6.39 dB at 110 GHz. Bandwidth is over 10 % and noise figure is 11.66 dB at 100 GHz. Fabricated coupler has shown insertion loss of 2~3 dB at 100~110 GHz band. Magnitude mismatch of coupler is below 1 dB and phase mismatch of coupler is below $5^{\circ}$.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.35.1-35.5
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• 2016

Background: Mucous retention cyst refers to a cyst made by expansion due to the blockage of the salivary gland near the maxillary sinus, and it is surrounded by epithelial cells. Most of them are small; therefore, they cannot be found well and are frequently with antral polyp. The aim of this study was to evaluate the clinical prognosis of sinus bone graft in patients with mucous retention cyst. Methods: This study was performed retrospectively on 23 patients who had sinus bone graft. Group 1 was 8 patients (10 sinuses) who had a mucous retention cyst, and group 2 was 15 patients (17 sinuses) who had no pathologic history about the maxillary sinus. For these patients, sinus bone graft was performed using the lateral approach technique. The total 51 implants were placed 6.22 weeks on the average after sinus bone graft. Sinus membrane perforation during operation, postoperative complications, marginal bone loss after restorative function, implant success rate, and survival rate were analyzed. Results: There was no complication in group 1, and there were three complications in group 2. In group 2, two cases of implants failed. The types of postoperative complications consisted of two minor infections and one wound dehiscence. Two implants of total 51 implants were removed, and the survival rate of implants was 96.08 % (group 1 100 %, group 2 93.5 %). The total success rate of implants was 92.2 % (group 1 95 %, group 2 90.3 %). Conclusions: The clinical prognosis was not affected by the presence of mucous retention cyst.

• Journal of Communications and Networks
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• v.10 no.3
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• pp.287-296
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• 2008

The IEEE 802.11 wireless standard uses the carrier sense multiple access with collision avoidance (CSMA/CA) as its MAC protocol (during the distributed coordination function period). This protocol is an adaptation of the CSMA/CD of the wired networks. CSMA/CA mechanism cannot guarantee quality of service (QoS) required by the application because orits random access method. In this study, we propose a new MAC protocol that considers different types of traffic (e.g., voice and data) and for each traffic type different priority levels are assigned. To improve the QoS of IEEE 802.11 MAC protocols over a multi-channel CSMA/CA, we have developed a new admission policy for both voice and data traffics. This protocol can be performed in direct sequence spread spectrum (DSSS) or frequency hopping spread spectrum (FHSS). For voice traffic we reserve a channel, while for data traffic the access is random using a CSMA/CA mechanism, and in this case a selective reject and push-out mechanism is added to meet the quality of service required by data traffic. To study the performance of the proposed protocol and to show the benefits of our design, a mathematical model is built based on Markov chains. The system could be represented by a Markov chain which is difficult to solve as the state-space is too large. This is due to the resource management and user mobility. Thus, we propose to build an aggregated Markov chain with a smaller state-space that allows performance measures to be computed easily. We have used stochastic comparisons of Markov chains to prove that the proposed access protocol (with selective reject and push-out mechanisms) gives less loss rates of high priority connections (data and voices) than the traditional one (without admission policy and selective reject and push-out mechanisms). We give numerical results to confirm mathematical proofs.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.83-88
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• 2000

When interpreting change over time in forest ecosystems, distinguishing the effects of forest succession from the effects of environmental stress can be difficult. The result may be a simplistic interpretation. citing a specific successional or environmental cause of forest change when both types may be occurring. We present two case studies of changes in the forest floor in northern hardwoods. First, the belief that 50% of soil organic matter is lost in the first 20 years after logging was based on a study comparing northern hardwood stands of different ages. We resampled a series of 13 such stands after an interval of 15 years, and found that the young stands were not, in fact. losing organic matter as rapidly as predicted from the original chronosequence study. The pattern of higher organic matter content in the forest floors of older stands compared to young stands could be equally well explained by changes in logging practices over the last century as by the aging of the stand. The observed pattern of forest floor organic matter as a function of stand age was previously interpreted as a successional pattern, ignoring changes in treatment history. In the second case study, observed losses of base cations from the forest floor were attributed to cation depletion caused by acid rain and declining calcium deposition. We found that young stands were gaining base cations in the forest floor; losses of base cations were restricted to older stands. Differences in litter chemistry in stands of different ages may explain some of the pattern in cation gains and losses. In this case, the contribution of successional processes to cation loss had been overlooked in favor of environmental stress as the dominant mechanism behind the observed changes. Studies of environmental stress use repeated measures over time. but often don't consider stand age as a factor. Studies of successional change often assume that environmental factors remain constant. We were able to consider both forest succession and external factors because we repeatedly sampled stands of different ages.