• Restorative Dentistry and Endodontics
• /
• v.31 no.5
• /
• pp.337-343
• /
• 2006

The purpose of this study was to estimate the relation between techniques used for microleakage from dye penetration and for marginal adaptation from SEM evaluation of the restoration. Using high speed #330 bur class V cavities ($4{\times}3{\times}1.5 mm$ around CEJ) were prepared on the buccal surface of 20 extracted human molars. Six dimples as reference points for SEM and dye penetration evaluation were made with 1/2 round bur. Cavity was bulk filled with microhybrid composite resin (Esthet X) and all-in-one adhesive (Xeno III). Teeth were stored in saline solution for one day, after then, they were finished and polished using Sof-Lex system. Fifty percent silver nitrate dye solution was used for the evaluation of microleakage and resin replica was used for marginal adaptation. All of these were done after 1000 times thermocycling between 5 and $55^{\circ}C$. Vertical sections were made through three dimples of restoration to obtain samples for the evaluation of dye penetration and inner marginal adaptation. Outer adaptational estimation was done with an intact restoration before sectioning. Dye penetration was determined in three degrees and percentage of outer and inner leaky margin was estimated from SEM image The data were analysed statistically: Spearman's rho test were used to check relationships between two methods. The result were as follows : 1. There were significant relationships between degree of dye penetration and inner and outer marginal adaptations each (p < 0.01). 2. However, there was no significant relationship between the results or inner and outer marginal adaptation. Within the results of this study, relationship between the percentage of marginal adaptation and microleakage shows significant relationship. However, inner and outer marginal adaptation did not show any significant relationship mutually.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.22 no.3
• /
• pp.337-342
• /
• 2000

Purpose : The purpose of this study was to analyze the lower third facial changes in frontal view after mandibular setback surgery. Materials and Methods : In this study, fifteen subjects(6 males and 9 females) with class III dental and skeletal malocclusions who were treated with BSSRO(Bilateral Sagittal Split Ramus Ostetomy) were used. Frontal cephalometric radiographs were taken preoperatively and more than 6 months postoperatively, and hard tissue(H2-Hl) and soft tissue changes (S2-S1) were measured on vertical and horizontal reference lines. In 15 cases, changes which developed more than 6 months after surgery were studied. Results : The results were as follows. 1. In the facial height, hard tissue $decreased(2.46{\pm}2.76mm)$ with statistical significance(P<0.01), and soft tissue also $decreased(1.64{\pm}3.66mm)$. As a result, the facial height generally becomes shorter after sagittal split ramus osteotomy. 2. In the mandibular width, hard tissue $decreased(2.08{\pm}3.59mm)$ with statistical sgnificance(P<0.05), but soft tissue $increased (2.14{\pm}5.73mm)$ without statistically significant difference(P>0.05) postoperatively. 3. In the facial index, hard tissue $decreased(0.23{\pm}2.21%)$, but soft tissue $increased(2.41{\pm}3.46%)$ with statistical significance. Conclusion : One of the main purpose of orthognathic surgery is to achieve facial esthetics and harmony. In order to fullfill this purpose, it is important to carry out a precise presurgical treatment planning by estimating the changes of frontal profile after surgery.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.6 s.121
• /
• pp.602-611
• /
• 2007

In this paper, the forward link of UHF RFID system is modeled in accordance with the EPCglobal class 1 generation 2(EPCglobal C1G2) UHF Radio-Frequency Identity protocol specification at $860{\sim}960MHz$. Based on the constructed model, characteristics on the forward link signal for the EPCglobal C1G2 RFID reader are simulated with the help of a MATLAB softwarein order to extract the design parameters of a transmit digital filter which meets the Korean RFID regulations. Herein, the forward link model is consisted of PIE source coding, transmit digital filter, modulation, local oscillator, and antenna. From the simulation results, the ranges of three design parameters(roll-off factor, cutoff frequency, the number of tabs) for transmit digital filter are obtained with different modulation techniques and the Tari(type a reference interval) values. Finally, DSB/SSB-ASK modulation technique can not satisfy the EPCglobal C1G2 specification when Tari equals to $6.25{\mu}sec$ in a multiple-reader environment. Consequently this paper can provide a guideline for design parameters of a RFID reader as well as the basic scheme of analyzing frequency interference problems in RFID environments, including multiple-reader and dense-reader environments.

• Proceedings of the KOSOMBE Conference
• /
• v.1991 no.05
• /
• pp.65-70
• /
• 1991

A hybrid model which uses a probabilistic model and a MLP(multi layer perceptron) model for pattern recognition of EMG(electromyogram) signals is proposed in this paper. MLP model has problems which do not guarantee global minima of error due to learning method and have different approximation grade to bayesian probabilities due to different amounts and quality of training data, the number of hidden layers and hidden nodes, etc. Especially in the case of new test data which exclude design samples, the latter problem produces quite different results. The error probability of probabilistic model is closely related to the estimation error of the parameters used in the model and fidelity of assumtion. Generally, it is impossible to introduce the bayesian classifier to the probabilistic model of EMG signals because of unknown priori probabilities and is estimated by MLE(maximum likelihood estimate). In this paper we propose the method which get the MAP(maximum a posteriori probability) in the probabilistic model by estimating the priori probability distribution which minimize the error probability using the MLP. This method minimize the error probability of the probabilistic model as long as the realization of the MLP is optimal and approximate the minimum of error probability of each class of both models selectively. Alocating the reference coordinate of EMG signal to the outside of the body make it easy to suit to the applications which it is difficult to define and seperate using internal body coordinate. Simulation results show the benefit of the proposed model compared to use the MLP and the probabilistic model seperately.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.7
• /
• pp.1319-1325
• /
• 2006

Urine analysis is basic test in clinical medicine using visual examination by expert nurse. Recently, this test is measured by automatic urine analysis system. But, this system has different results by each instrument. So, a new classification algorithm is required for accurate classify and urine color collection. In this paper, a intelligent color classifier of urine analysis system was designed using neural network algorithm. The input parameters are three stimulus(RGB) after preprocessing using normalization. The fuzzy inference and neural network ware constructed for classify class according to 9 urine test items and $3{\sim}7$ classes. The experiment material to be used a standard sample of medicine. The possibility to adapt classifier designed for urine analysis system was verified as classifying measured standard samples and observing classified result. Of many test items, experimental results showed a satisfactory agreement with test results of reference system.

• Korean Institute of Interior Design Journal
• /
• v.21 no.1
• /
• pp.203-210
• /
• 2012

Since a private museums started in Europe 17C, many private museums established for high-class people like aristocrats to collect and to keep art works and to appreciate for limited members. After the French Revolution in 18C, the publicity became an important social issue through all European regions, and the museum gradually changed into public ones. Like that, as the concept of museum changed, its social role as well as its function was also changed. The concept of collection and display or preservation changed into the concept of exhibition and appreciation featuring the publicity. With the year-round exhibition, a classical concept, the planned-exhibition, a new active concept set as an important factor for a museum's projects. The latter concept embraces new social issues. Therefore as the space for planned-exhibitions reflecting social issues every season was needed, a museum sets its planned-exhibition space with the changeability, and gradually expands this kind of space in size. It is expected that planned-exhibition spaces characterized as the changeability may give some changes on the flow of a museum's overall space, and may have substantial influences on the flow. To recognize the changes in a planned-exhibition space's influence on the museum, this study selected some national, public museums having the planned-exhibition space, and investigated their influences on each museum's overall space structure through the analysis on space syntax. This study assumed the change of planned-exhibition space as the changes in the number of convex spaces, and measured it. And to understand the planned-exhibition's changes on a museum's overall spaces, such changed assumed as the numeric changes in convex spaces and measured them. In addition, the numeric changes's influence on the overall space structure was analyzed by measuring the overall space's average integration level. Through the above two factors, the 3 research methodologies and analyzed results were drawn out.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.46 no.8
• /
• pp.71-78
• /
• 2009

An 8${\times}$8-Gb/s/channel 4-PAM transceiver was designed for high speed memory applications by using 70nm DRAM process with 1.35V supply. An asymmetric 4-PAM signaling scheme is proposed to increase the voltage and time margin of upper and lower eyes in 3-class eye opening. A mathematical basis shows that this scheme statistically reduces 33% of reference noise effect in a receiver. Also, an adaptive pre-emphasis scheme, which utilizes a lone-bit pulse with integrator at the receiver, is introduced to reduce ISI for a simple DRAM channel. In this scheme, an integrating clock timing calibration by using a pre-determined pattern is proposed for the optimum ISI measurement.

• Structural Engineering and Mechanics
• /
• v.62 no.1
• /
• pp.21-31
• /
• 2017

Engineered Cementitious Composite (ECC) is a special class of the new generation of high performance fiber reinforced cementitious composites (HPFRCC) featuring high ductility with relatively low fiber content. In this research, the mechanical performance of ECC beams will be investigated with respect to the effect of slag and aggregate size and amount, by employing nonlinear finite element method. The validity of the models was verified with the experimental results of the ECC beams under monotonic loading. Based on the numerical analysis method, nonlinear parametric study was then conducted to evaluate the influence of the ECC aggregate content (AC), ECC compressive strength ($f_{ECC}$), maximum aggregate size ($D_{max}$) and slag amount (${\phi}$) parameters on the flexural stress, deflection, load and strain of ECC beams. The simulation results indicated that when increase the slag and aggregate size and content no definite trend in flexural strength is observed and the ductility of ECC is negatively influenced by the increase of slag and aggregate size and content. Also, the ECC beams revealed enhancement in terms of flexural stress, strain, and midspan deflection when compared with the reference beam (microsilica MSC), where, the average improvement percentage of the specimens were 61.55%, 725%, and 879%, respectively. These results are quite similar to that of the experimental results, which provides that the finite element model is in accordance with the desirable flexural behaviour of the ECC beams. Furthermore, the proposed models can be used to predict the flexural behaviour of ECC beams with great accuracy.

• Journal of the Korean Home Economics Association
• /
• v.41 no.5
• /
• pp.179-191
• /
• 2003

The study is to suggest easier making method of skirts and slacks as to compare production process between manufacturers and references of clothing construct in universities. Skirts and slacks have simple production process and they are basic subjects in clothing construct class. But most references have just contents which are to make basic styles of skirts and slacks made basic materials. Continuous development of new material and variety of style request more efficient and easer making method in the reference of clothing construct. So the making methods of references and manufacturers are compared and analyzed in this study In references, there are many hand work and sub-work because they are for a person who make own clothes. In contrast, manufacturers have to product many variety clothes of good quality for many people and think the production cost of clothes. They use more simple and efficient method that include their know-how to meet changing fashion situation. In making methods of skirts and slacks, differences between references and manufacturer are in sewing of waist band and zippers and location of interlining. Manufacturers use variedly sewing method of waist band according to material and their experience. Especially handling for wrong side inseam of waist band is distinct between references and manufacturers. References have basic and detail work and manufacturers know processing order having even grade work to keep continuous production. The making method of clothes have to change and improve according to the situation. The more useful making method get to include their merits and references need to add more practical method and knowledge.

• Korean Journal of Remote Sensing
• /
• v.29 no.5
• /
• pp.537-544
• /
• 2013

Baton Peninsula, where Sejong station is located, mainly covered with snow and vegetation. Because this area is sensitive to climate change, monitoring of surface variation is important to understand climate change on the polar region. Due to the inaccessibility, the remote sensing is useful to continuously monitor the area. The objectives of this research are 1) map classification of land-cover types in the Barton Peninsular around King Sejong station and 2) grasp distribution of vegetation species in classified area. A KOMPSAT-2 multispectral satellite image was used to classify land-cover types and vegetation species. We performed classification with hierarchical procedure using KOMPSAT-2 satellite image and ground reference data, and the result is evaluated for accuracy as well. As the results, vegetation and non-vegetation were clearly classified although species shown lower accuracies within vegetation class.