광 주입 파장 잠금 반도체 레이저를 이용한 광학 복소 신호 생성시의 주입 매개 변수 정확도 향상

조준형,성혁기 한국정보통신학회 2021 한국정보통신학회논문지 Vol.25 No.3

광 주입 잠금 반도체 레이저의 주입 매개 변수를 조절하여 광학적 복소 신호를 생성 할 수 있다. 그러므로 정확한 주입 매개 변수의 결정은 광학적 복소 신호 생성 기술에서의 핵심 요소이다. 기존의 주입 매개 변수의 추출 이론은 광 주입 잠금 반도체 레이저의 비율 방정식을 사용하며, 이는 locking map 기반의 보간법을 사용하기 때문에 정확한 주입 매개 변수의 추출에 한계가 있다. 이를 해결하기 위하여 비율 방정식의 새로운 해석법을 제안한다. 제안된 해석법은 비율 방정식을 광학적 복소 신호의 생성에 맞게 수정하여 주입 매개 변수를 직접적으로 도출하는 방법이며, 이를 통하여 보간법을 통한 복소 신호 생성 대비 103 배의 오차 감소를 달성하였다. An injection locking technology of a semiconductor laser is a promising technology to generate optical complex signals by adjusting optical injection parameters. The extraction of the precise injection parameters plays a key role in the generation of the optical complex signal. Rate equations of semiconductor lasers under optical injection are commonly used to map the injection parameters and the corresponding optical complex signal. The accuracy of the generated optical complex signal on the injection parameters is limited since the rate equations require a locking map-based interpolation method. We propose a novel analytic method, namely rate equation-based direct extraction method, to directly calculate the injection parameters without relying on the locking map-based interpolation method. We achieved 103-times improvement of the signal accuracy by using the proposed method compared to locking-map based interpolation method.

사출성형을 이용한 마이크로 도광판의 성형에 관한 연구

조창연,신홍규,박동영,홍남표,김병희 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

The Injection molding process has a high accuracy, good reproducibility in high numbers and at lows cost. However, it has been known that it is hard to understand the size limitation and requirement for a very highly pressure and various parameters. In order to overcome these problems, we developed an injection molding system for production of micro-LGP(Light Guide Plate) and carried out various experiments with respect to injection pressure, molding temperature, back pressure, and molding time etc. And also, in order to overcome molding defects such as flow marks, non-fill, and sticking etc., the peltier elements for stable control of molding temperature was used. Through various experiments and analyses, the performance and validity of our injection molding system confirmed. Finally, we compared results and parameters of an injection molding system with those of a hot embossing system. Consequently, we proved that, compared with a hot embossing process, an injection molding process will likely have a better performance, cost-effectiveness and yield.

펜타캠을 이용한 유리체강내 주입술 후 전방인자 변화 분석

김병선,김체론,김성재,한용섭,서성욱,유지명,정인영,박종문 대한안과학회 2013 대한안과학회지 Vol.54 No.12

Purpose: To evaluate the changes of anterior chamber parameters and intraocular pressure (IOP) with Pentacam<SUP>® after intravitreal injection.<br /> Methods: A total of 76 eyes of 76 patients received an intravitreal injection of either triamcinolone acetonide (TA) or bevacizumab. Twelve patients were treated with an intravitreal injection of TA 0.1 ml, 16 patients were treated with an intravitreal injection of TA 0.05 ml, while the remaining 48 patients received a bevacizumab 0.05 ml injection. All patients underwent anterior chamber depth, anterior chamber angle, and anterior chamber volume evaluation with Pentacam<SUP>® before and 5 minutes after injection. Additionally, IOP measurements were taken 5 minutes before and 5 minutes, 30 minutes, 1 hour and 1 day after injection.<br /> Results: Anterior chamber depth, anterior chamber angle, anterior chamber volume, and IOP changes in patients receiving TA 0.1 ml were 0.4 ± 0.11 mm, 10.2 ± 4.1°, 33.7 ± 5.9 mm3 and 18.8 ± 12.1 mm Hg, respectively. Anterior chamber depth, anterior chamber angle, anterior chamber volume, and IOP changes in patients receiving TA 0.05 ml were -0.01 ± 0.05 mm, 2.4 ± 3.2°, 5.8 ± 9.5 mm3 and 4.8 ± 7.4 mm Hg, respectively. Anterior chamber depth, anterior chamber angle, anterior chamber volume, and IOP changes in patients receiving bevacizumab were 0.28 ± 0.99 mm, 0.8 ± 4.0°, 7.1 ± 9.6 mm3 and 5.4 ± 6.3 mm Hg, respectively. There was a significant difference between TA 0.1 ml and 0.05 ml. However, there was no significant difference between TA 0.05 ml and bevacizumab 0.05 ml.<br /> Conclusions: Because of similar anterior chamber parameters changes after 0.05 ml intravitreal injection with TA or bevacizumab, early period IOP increases due to intravitreal volume expansion. Intravitreal 0.05 ml injections do not require any other procedures for controlling IOP 30 minutes after injection.<br /> J Korean Ophthalmol Soc 2013;54(12):1824-1831

사출성형을 이용한 마이크로 도광판의 성형에 관한 연구

조창연(C. Y. Jo),신홍규(H. G. Shin),박동영(D. Y. Park),홍남표(N. P. Hong),김병희(B. H. Kim) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

The Injection molding process has a high accuracy, good reproducibility in high numbers and at lows cost. However, it has been known that it is hard to understand the size limitation and requirement for a very highly pressure and various parameters. In order to overcome these problems, we developed an injection molding system for production of micro-LGP(Light Guide Plate) and carried out various experiments with respect to injection pressure, molding temperature, back pressure, and molding time etc. And also, in order to overcome molding defects such as flow marks, non-fill, and sticking etc., the peltier elements for stable control of molding temperature was used. Through various experiments and analyses, the performance and validity of our injection molding system confirmed. Finally, we compared results and parameters of an injection molding system with those of a hot embossing system. Consequently, we proved that, compared with a hot embossing process, an injection molding process will likely have a better performance, cost-effectiveness and yield.

사출성형을 이용한 마이크로 도광판의 성형에 관한 연구

조창연(C. Y. Jo),신홍규(H. G. Shin),박동영(D. Y. Park),홍남표(N. P. Hong),김병희(B. H. Kim) 한국생산제조학회 2006 한국생산제조시스템학회 학술발표대회 논문집 Vol.2006 No.5

The Injection molding process has a high accuracy, good reproducibility in high numbers and at lows cost. However, it has been known that it is hard to understand the size limitation and requirement for a very highly pressure and various parameters. In order to overcome these problems, we developed an injection molding system for production of micro-LGP(Light Guide Plate) and carried out various experiments with respect to injection pressure, molding temperature, back pressure, and molding time etc. And also, in order to overcome molding defects such as flow marks, non-fill, and sticking etc., the peltier elements for stable control of molding temperature was used. Through various experiments and analyses, the performance and validity of our injection molding system confirmed. Finally, we compared results and parameters of an injection molding system with those of a hot embossing system. Consequently, we proved that, compared with a hot embossing process, an injection molding process will likely have a better performance, cost-effectiveness and yield.

품질기능전개와 신경망 회로를 이용한 사출성형 공정변수의 예측

고범욱,김종성,최후곤 대한산업공학회 2008 산업공학 Vol.21 No.2

The injection molding process is able to produce high precision manufactures as a single process with fast speed. However, the prices of both the mold and the molding machine are expensive, and the single process is very complex and difficult to compose of the exact relationship between the process setting conditions and the product quality. Therefore, the quality of a molded product often depends on a skillful engineer's operations in the design of both parts and molds. In this paper, the relationship between the process conditions and the defectiveness is built for better manufactures under settings of the appropriate parameters, and so it can reduce the setup time in the injection molding process. Quality Function Deployment (QFD) provides severe defectiveness factors along with the related process parameters. Also, neural networks estimate the relationship between defective factors and process setting parameters, and lead to reduce the defectiveness of molded parts.

Development of Parameter Optimization System using Iterative Experiment and Optimization for Injection Foam Molding

Kyung-min Lee(이경민) 제어로봇시스템학회 2017 제어·로봇·시스템학회 논문지 Vol.23 No.12

Injection molding (IM) is one of the most important processes for mass-producing plastic products. There are several significant challenges in using IM. The IM process requires many input parameters, but the relationships between the desired material properties and parameter settings (e.g. gas content and pressure drop) are not well understood collectively. We propose an optimization-based computational framework that will provide computer-based decision support for setting parameters in the IM process. The decision support will enable dramatic time and cost efficiencies in that the settings for parameters. It can discover optimized parameters much more rapidly than conventional methods that require extensive experimentation. Key elements in the framework involve approximating the governing equations using analysis of variance (ANOVA) techniques and normative optimization modeling to achieve optimal parameter settings. We illustrate the computational framework on HDPE materials in which parameter settings such as gate geometry, N2 content, void fraction, and injection speed are considered. The proposed framework will provide an improved understanding of the relationships between material properties and parameter settings in general IM process environments.

사출성형공정에서 다수 품질 예측에 적용가능한 다중 작업 학습 구조 인공신경망의 정확성에 대한 연구

이준한,김종선 한국금형공학회 2022 한국금형공학회지 Vol.16 No.3

In this study, an artificial neural network(ANN) was constructed to establish the relationship between process condition prameters and the qualities of the injection-molded product in the injection molding process. Six process parmeters were set as input parameter for ANN: melt temperature, mold temperature, injection speed, packing pressure, packing time, and cooling time. As output parameters, the mass, nominal diameter, and height of the injection-molded product were set. Two learning structures were applied to the ANN. The single-task learning, in which all output parameters are learned in correlation with each other, and the multi-task learning structure in which each output parameters is individually learned according to the characteristics, were constructed. As a result of constructing an artificial neural network with two learning structures and evaluating the prediction performance, it was confirmed that the predicted value of the ANN to which the multi-task learning structure was applied had a low RMSE compared with the single-task learning structure. In addition, when comparing the quality specifications of injection molded products with the prediction values of the ANN, it was confirmed that the ANN of the multi-task learning structure satisfies the quality specifications for all of the mass, diameter, and height.

머신러닝을 이용한 다공형 GDI 인젝터의 플래시 보일링 분무 예측 모델 개발

상몽소,신달호,Quangkhai Pham,박수한 한국분무공학회 2022 한국액체미립화학회지 Vol.27 No.2

The purpose of this study is to use machine learning to build a model capable of predicting the flash boiling spray characteristics. In this study, the flash boiling spray was visualized using Shadowgraph visualization technology, and then the spray image was processed with MATLAB to obtain quantitative data of spray characteristics. The experimental conditions were used as input, and the spray characteristics were used as output to train the machine learning model. For the machine learning model, the XGB (extreme gradient boosting) algorithm was used. Finally, the performance of machine learning model was evaluated using R2 and RMSE (root mean square error). In order to have enough data to train the machine learning model, this study used 12 injectors with different design parameters, and set various fuel temperatures and ambient pressures, resulting in about 12,000 data. By comparing the performance of the model with different amounts of training data, it was found that the number of training data must reach at least 7,000 before the model can show optimal performance. The model showed different prediction performances for different spray characteristics. Compared with the upstream spray angle and the downstream spray angle, the model had the best prediction performance for the spray tip penetration. In addition, the prediction performance of the model showed a relatively poor trend in the initial stage of injection and the final stage of injection. The model performance is expired to be further enhanced by optimizing the hyper-parameters input into the model.

Design of Polymeric Orthopedic Screws with Variable Stiffness and Multi-Objective Optimization of Injection Molding Process

Sunil Kumar Yadav,Arnab Sikidar,Dinesh Kalyanasundaram 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.4

Background Orthopedic metallic screws even post healing causes ‘pinching eff ect’ and load infl ammation to the bone. In this work, the design and development of a novel metallic core and polymeric shell orthopedic screw is discussed along with optimization of manufacturing process. Methods A comparative 2D fi nite element study for pull-out test was conducted on HA, HB, HC, and HD standards of screws for approximately identical diameters to determine the type of threading for the proposed design of the novel orthopedic screw. The polymeric shell of the orthopedic screws was manufactured by injection molding process. The material used for manufacturing the polymeric shell was poly-l-lactic acid. Injection pressure, injection velocity, packing pressure and packing time of the injection molding process were optimized for the following output responses: maximum axial pull-out strength, and maximal bending strength of the screw. Results The r-squared and the adjusted r-squared value of the developed regression model for pull-out was found to be 96% and 92%, respectively. For the bending force, the developed regression model had a r-squared and adjusted r-squared value of 87% and 75%, respectively. The regression models were maximised to obtain the desired input parameters. The optimised parameters were validated experimentally at two local maxima for both pull-out and bending force. Signifi cance The developed screw is novel in design and a patent has been fi led under US patent offi ce with number US 2022/0000529 A1. The screws can be used by medical practitioners to avoid or minimise revision surgery and infl ammation.