• Archives of Plastic Surgery
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• v.33 no.5
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• pp.659-662
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• 2006

Purpose: Alloplastic implants, such as methylmethacrylate, Teflon, silicone, Supramid are commonly used to cover the floor defect and to prevent reherniation of the displaced orbital tissue in orbital floor fracture. Silicone implant has been used for reconstruction of orbital wall defects because of pliability, advantage of carving and chemically inert nature. However, silicone implant also has complications including infection, extrusion, pain, dystopia and tissue reaction. Cyst formation around the silicone implant is a very rare complication. According to many reports, cysts around alloplastic implant in an orbital area are mostly hemorrhagic cysts consisted of blood breakdown product with fibrous capsule cell in histologic examination. Methods: The authors report atypical case and successful treatment of intraorbital hemorrhagic cyst around silicone implant of a 37-year-old male patient. Results: Preoperative symptoms of diplopia, exophthalmos, proptosis, vertical dystopia and ectropion of lower eyelid were resolved after surgical removal of implants with surrounding capsule. Conclusion: Clinical suspicion of plastic surgeon is important in diagnosis of intraorbital cyst of patients who have history of silicone implantation and computed tomography is the standard tool of diagnosis. During the operation, caution must be taken on delivering the whole capsule of intraorbital cyst along with silicone implant to prevent recurrence of the cyst.

• Journal of Biosystems Engineering
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• v.33 no.1
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• pp.30-37
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• 2008

Dynamic excitation and response analysis is an acceptable method to determine some of physical properties of agricultural product for quality evaluation. There is a difference in the internal viscoelasticity between sound and defective fruits due to the difference of geometric structures, thereby showing different vibration characteristics. This study was carried out to develop a portable piezoelectric film-based glove sensor system that can separate internally damaged watermelons from sound ones using an acoustic impulse response technique. Two piezoelectric sensors based on polyvinylidene fluoride (PVDF) films to measure an impact force and vibration response were separately mounted on each glove. Various signal parameters including number of peaks, energy ratio, standard deviation of peak to peak distance, zero-crossing rate, and integral value of peaks were examined to develop a regression-estimated model. When using SMLR (Stepwise Multiple Linear Regression) analysis in SAS, three parameters, i.e., zeros value, number of peaks, and standard deviation of peaks were selected as usable factors with a coefficient of determination ($r^2$) of 0.92 and a standard error of calibration (SEC) of 0.15. In the validation tests using twenty watermelon samples (sound 9, defective 11), the developed model provided good capability showing a classification accuracy of 95%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.11
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• pp.2037-2042
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• 2017

The manufacturing facility is generally operated by a pre-set program under the existing factory automation system. On the other hand, the manufacturing facility must decide how to operate autonomously in Industry 4.0. Determining the operation mode of the production facility itself means, for example, that it detects the abnormality such as the deterioration of the facility at the shop-floor, prediction of the occurrence of the problem, detection of the defect of the product, In this paper, we propose a manufacturing process modeling using a queue for detection of manufacturing process abnormalities at the shop-floor, and detect abnormalities in the modeling using SVM, one of the machine learning techniques. The queue was used for M / D / 1 and the conveyor belt manufacturing system was modeled based on ${\mu}$, ${\lambda}$, and ${\rho}$. SVM was used to detect anomalous signs through changes in ${\rho}$.

• The Journal of Engineering Research
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• v.6 no.1
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• pp.15-27
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• 2004

The first aim of mass product of glass in Automatic bottle glass industry is to decrease the cost and to increase the quality. Second, the cullet is how widely used to save the energy and reducing of ecomaterials. However the physical and chemical properties of Soda-lime glass would be come true at the lower than 2% $Al_2 O_3$. Unfortunately the $Al_2 O_3$ contents of domestic silica is greater than 4% Since small glass class than 200ml bottle is made in domestic silica the producting efficiency would be decreased due to the defect such as cord, knot, devitrite, pore etc. There are many problems such as devitrifiacation and deteriorated effect on production in glass industry became of increasing of plate glass cullet. It is tried to solve these kinds of problems using various analysing methods in this experiments.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.317-325
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• 1995

This study was performed to investigate the mean life expectancy of dental prosthetic restorations. The author has examined 352 dental prosthesis clinically and radiologically, and decided the success(survival) and failure(mortality) of the dental prosthesis. The dental prosthesis which had been treated in the Seoul National University Dental Hospital, two private clinics in Seoul, one university dental hospital, and two private clinics in local province were included in this study. The survival analysis using product limit estimator was used and the mean life expectancy of each type of dental prosthesis was calculated. The results were as follows : 1. The life expectancies were 10.5 years in gold crown and bridge, 8.5 years in porcelain fused to metal crown and bridge, 8.3 years in nonprecious metal crown and bridge, 8.1 years in removal partial denture, and 7.7 years in full denture. 2. The causes of mortality were in the order of dental caries(24.6%), fracture of dental prosthesis(19.2%), periodontal problems(18.6%), chronic chewing difficulty and dysfunction due to dental prosthesis(15.0%), excessive exposure of abutments due to the marginal defect of dental prosthesis(14.4%), abnormal occlusion due to severe attrition of artificial teeth in dentures(3.0%), periapical problems(2.4%), perforation of dental prosthesis(1.8%), and loose contacts with neighboring tooth(1.2%). 3. Among survival cases, 66.5% showed normal chewing ability and 31.9% showed partial chewing ability. However, 1.6% of them complained loss of chewing ability. 4. Among failure cases, 6.6% showed normal chewing ability and 38.9% showed partial chewing ability. However, 54.5% of them complained loss of chewing ability.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.262-268
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• 2010

Organic light emitting diode is developed fast from 1963 after discovering electric light emitting phenomenon. First PMOLED(passive matrix OLED) product is manufactured and AMOLED(active matrix OLED) using TFT(thin film ransistor) is now in the center. PMOLED is mainly mounted at sub display. but AMOLED is mounted at main display. Also AMOLED expand the market to PMP(portable multimedia players), navigation and TV. Even thought OLED's market is opening to many applications, OLED is worried about lifetime until now. That's appeared in market in a very short time and is not known well about result of OLED's lifetime and reliability test. And there is no standard ssessment method and not enough study to standardization the method. A study's purpose is reduce the time for life test by accelerated current and it can do production possible design by accelerated life model in design phase. It's must be add to process variables and design variables(like ratio of light emitting, organic material structure, condition of aging, etc) to make the best use of supplied accelerated lifetime model in this paper. In terms of lifetime it needs each criterion of applications because of image sticking. In conclusion, it's possible to discover new defect because there is not much time to be opened in market and develop a method of manufacturing process & materials, so we need to study on the subject of this paper continuously.

• Journal of IKEEE
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• v.19 no.1
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• pp.64-72
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• 2015

In this paper, we have developed the gantry automation system via information technology (IT) to improve the productivity of fuel filter manufacturing process. The monitoring system of manufacturing process plays an important role in analyzing the defective products as well as improving the production yield rate. The experimental results of 3 months with 10000 samples validate that the error rate is decreased from 0.65 % to 0.45 %. Also, the defect of raw material is decreased via monitoring of material tools which can notify the time for replacement and accurate insertion of raw materials to the loader. The productivity is increased by reducing the process time from 94.7 sec to 78.8 sec per raw material through comparing the whole manufacturing courses : from inserting of raw material to outcome of product. The process time is decreased by 20.2 % by automation of inserting and outcome course. Moreover, safety of worker as well as reduction of transfer time are highly related with increase of productivity.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.125-133
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• 2016

From the first application of a thermoelectric module to nowtoday, it has been more than half a century. The application of a thermoelectric module is becoming more and more widely accepted since, people's requirement rely more and more on the efficiency of thermoelectric modules and their reliability become higher and higher. So people pay more and more attention to the thermoelectric module. In Around the world, the more research for into improving the efficiency of thermoelectric modules is focused on the current materials. at present. However, the research of into available materials had has some limitations, and the research of materials had reached a bottleneckthere are limits to current applications. On the other hand, from the production process, if we assembled by materials withoutmodules without any damages and achieve the ideal state of a joint, we can make the a product to maximize performance and have a longer service life. SoTherefore, in this study we will prove the relationship between the any defects inside and the efficiency of a thermoelectric module to improve the quality management and performance of modern thermoelectric modules at present.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.4
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• pp.110-121
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• 2009

It is essential to embed product quality in the design process to win the global competition. Many components found in many products including automobiles and electronic devices are fabricated using sheet metal forming processes. Wrinkle and fracture are two types of defects frequently found in the sheet metal forming process. Reducing such defects is a hard problem as they are affected by many uncontrollable factors. Attempts to solve the problem based on traditional deterministic optimization theories are often led to failures. Furthermore, the wrinkle and fracture are conflicting defects in such a way that reducing one defect leads to increasing the other. Hence, it is a difficult task to reduce both of them at the same time. In this research, a new design method for reducing the rates of conflicting defects under uncontrollable factors is presented by using operating window and a sequential search procedure. A new SN ratio is proposed to overcome the problems of a traditional SN ratio used in the operating window technique. The method is applied to optimizing the robust design of a sheet metal forming process. To show the effectiveness of the proposed method, a comparison is made between the traditional and the proposed methods using simulation software, applied to a design of particular sheet metal forming process problem. The results show that the proposed method always gives a more robust design that is less sensitive to noises than the traditional method.

• Tribology and Lubricants
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• v.32 no.4
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• pp.113-118
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• 2016

As an economic, high quality, and highly reliable gear with low noise and low vibration is demanded, an overall finite element analysis regarding a gear is required. Also, an infrared thermography test, which is a quantitative testing technique, is demanded for safety and longer lifespan of gear products. In order to manufacture a gear product or to determine safety of a gear being used, it is necessary to precisely determine ingredients of a material constituting a gear and detect any internal defect. This study aims to realize a design that minimizes the spur gear displacement with respect to power during its rotation and ensures the spur gear control capacity by using a 3D model and the midasNFX program. This facilitates the assessment of the possibility of cracking by evaluating the stress intensity and focusing on the integrity of the spur gear. We prepare the specimen of the spur gear based on the possibility of cranking as per the result of the structural interpretation from an infrared ray thermal measuring technique. After cooling the spur gear, we perform experiments using thermography and halogen lamps and analyze the temperature data according to the results of the experiment. In the experiment which we use thermography after cooling, we find a rise in the temperature of the room. As a result, the defective part show temperatures lower than their surroundings while the normal parts have temperatures higher than the defective parts. Therefore, it possible to precisely identify defective part owing to its low temperature.