• 한국IT서비스학회지
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• 제21권2호
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• pp.97-107
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• 2022

Recently, interest in smart factories is increasing. Investments to improve intelligence/automation are also being made continuously in manufacturing plants. Facility automation based on sensor data collection is now essential. In addition, we are operating our factories based on data generated in all areas of production, including production management, facility operation, and quality management, and an integrated standard information system. When producing LCD polarizer products, it is most important to link trace information between data generated by individual production processes. All systems involved in production must ensure that there is no data loss and data integrity is ensured. The large-capacity data collected from individual systems is composed of key values linked to each other. A real-time quality analysis processing system based on connected integrated system data is required. In this study, large-capacity data collection, storage, integration and loss prevention methods were presented for optimization of LCD polarizer production. The identification Risk model of inspection products can be added, and the applicable product model is designed to be continuously expanded. A quality inspection and analysis system that maximizes the yield rate was designed by using the final inspection image of the product using big data technology. In the case of products that are predefined as analysable products, it is designed to be verified with the big data knn analysis model, and individual analysis results are continuously applied to the actual production site to operate in a virtuous cycle structure. Production Optimization was performed by applying it to the currently produced LCD polarizer production line.

• 동력기계공학회지
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• 제20권5호
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• pp.78-85
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• 2016

This paper considers the influence of internal heat exchangers to the efficiency of a refrigerating system using R170. These liquid-gas heat exchangers(internal or suction-line heat exchangers) can, in some cases, yield improved system performance while in other cases they degrade system performance. A steady state mathematical model is used to analysis the performance characteristics of refrigeration system with internal heat exchanger. The influence of operating conditions, such as the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, to optimal dimensions of the heat exchanger is also analyzed in the paper. The main results were summarized as follows : the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, and effectiveness have an effect on the cooling capacity, compressor work and RCI(Relative Capacity Index) of this system. Exception for the effect of inner diameter, the RCI of R170 with respect to refrigerant mass flowrate, the length and effectiveness of internal heat exchanger is about 2.1~3.3% higher than that of R13 at the same experimental conditions. With a thorough grasp of these effect, it is necessary to design the R170 compression refrigeration cycle using internal heat exchanger.

• 한국강구조학회 논문집
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• 제10권1호통권34호
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• pp.25-35
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• 1998

각형 강관 기둥과 H형 보의 접합부에 대한 연구는 보의 하중을 기둥에 전달하는 과정에서 생기는 응력의 집중현상 때문에 하중을 효율적으로 전달하는 방식을 고안하는 것에 초점을 맞추었다. 본 연구에서는 외부보강형 접합부의 강도를 증가시키기 위한 방법으로 직사각형의 스티프너를 사용하였다. 실물의 절반크기로 시험체를 제작하여 단순 인장실험을 실시하였다. 항복선이론과 가상일법을 이용하여 접합부의 극한강도를 추정하는 공식을 유도하였으며 실험치에 근접한 결과를 얻었다.

• Geomechanics and Engineering
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• 제9권6호
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• pp.729-742
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• 2015

The aim of the present work was the study of instability in a loose sand from Les Dunes beach in Ain Beninan, Algeria, where the Boumerdes earthquake occurred in 2003. This earthquake caused significant structural damages and claimed the lives of many people. Damages caused to infrastructures were strongly related to phenomena of liquefaction. The study was based on the results of two drained and six undrained triaxial tests over a local sand collected in a region where liquefaction occurred. All the tests hereby analyzed followed compression stress-paths in monotonic conditions and the specimens were isotropically consolidated, since the objective was to study the instability due to static loading as part of a more general project, which also included cyclic studies. The instability was modeled with the second-order work increment criterion. The definition of the instability line for Les Dunes sand and its relation with yield surfaces allowed the identification of the region of potential instability and helped in the evaluation of the susceptibility of soils to liquefy under undrained conditions and its modeling. The dilatancy rate was studied in the points where instability began. Some mixed tests were also simulated, starting with drained conditions and then changing to undrained conditions at different time steps.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.108-112
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• 2023

Precision manufacturing technology is rapidly developing due to the extreme miniaturization of semiconductor processes to comply with Moore's Law. Accurate and precise alignment, which is one of the key elements of the semiconductor pre-process and post-process, is very important in the semiconductor process. The center detection of wafer align marks plays a key role in improving yield by reducing defects and research on accurate detection methods for this is necessary. Methods for accurate alignment using traditional image sensors can cause problems due to changes in image brightness and noise. To solve this problem, engineers must go directly into the line and perform maintenance work. This paper emphasizes that the development of AI technology can provide innovative solutions in the semiconductor process as high-resolution image and image processing technology also develops. This study proposes a new wafer center detection method through variable thresholding. And this study introduces a method for detecting the center that is less sensitive to the brightness of LEDs by utilizing a high-performance object detection model such as YOLOv8 without relying on existing algorithms. Through this, we aim to enable precise wafer focus detection using artificial intelligence.

• 한국조사연구학회지:조사연구
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• 제8권1호
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• pp.1-30
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• 2007

본 연구에서는 6시그마에서 기대한 성과를 얻으려면 도입과정에서 일련의 단계를 거쳐야 한다는 가정을 하였으며 특히 조직성숙이 성과에 미치는 영향을 분석하고 있다. 6시그마에서 성과를 얻는 단계를 준비단계, 수용단계, 성숙단계로 정의하여 단계적 모형을 제시하였다. 준비단계는 다시 조직변화오인, 추진시스템요인으로 세분하였고, 결과변수인 성과는 시장경쟁력성과, 조직구성원성과, 재무성과로 구분하였다. 6시그마를 도입하여 기대한 성과를 얻으려면 이 단계를 순차적으로 거쳐야 한다는 가정을 토대로 단계모형과 경쟁모형을 설정하여 구조방정식 모형을 통하여 비교 분석하였다. 기업을 표본단위로 한 판단표집(judgement sampling)을 통해 설문자료를 수집 처리하였다. 최종적인 분석에는 281 업체에서 수집된 자료가 사용되었다. 6시그마를 도입하고자 하는 기업은 준비단계, 수용단계, 그리고 성숙단계까지 도달해야만 기대한 성과를 얻을 수 있다는 것을 분석결과로 제시한다. 즉, 준비와 수용만 되었다고 큰 성과를 얻는다기보다는 성숙단계까지 가야만 성과를 제대로 얻을 수 있음을 시사하고 있다.

• 수산경영론집
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• 제38권2호
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• pp.41-62
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• 2007

The Fish aquacultural Industry has been developed rapidly since 1990s in Korea. The total production of fish aquaculture was 5,000ton in the beginning of 1990s, but it was an excess of 80,000ton in 2005. In the beginning of 1990s, the percentage of flatfish yield was 80% of the fish aquaculture in the respect of production. And it has been maintained 50% level in 2005. In this point of view, flatfish aquaculture played the role of leader in the development of fish aquaculture. Rapid increasing of production was not only caused to decreasing in price basically, but also it threatened the management of producer into insecure price for aquacultural flatfish. Therefore, it needs the policy for stabilizing in price, but it is difficult to choose the method because the basic study was not accomplished plentifully. This study analyzed about price structure of aquacultural flatfish. A period of analysis was from January 2000 to December 2005, and a data was used monthly data for price. The principal result of this study is substantially as follows. 1) The price of producing and consuming district is closely connected. 2) A gap between producing district price and consuming district price is decreasing recently, It seems to be correlated with outlook business of aquacultural flatfish. 3) Trend line of the price was declining until 2002, but it turned up after that. The other side, circulated fluctuation was being showed typically. 4) The circle of circulated fluctuation was growing longer, so it seems that the producer was doing a sensible productive activity to cope with changing price. As a result, government's policy needs to be turned into price policy from policy of increased production for aquacultural flatfish. It seems that the best policy is price stabilization polices. And also, government needs to invest in outlook business for aquaculture constantly.

• 자원환경지질
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• 제26권4호
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• pp.541-549
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• 1993

The main goal of this paper is to determine hydraulic properties and to predict drawdown for the efficient and stable development of groundwater in the Daejong-Chun area, North of Kyungsang-Do. Based on geological survey and analysis of well logging data conducted in 1991, it is found that the type of aquifer of this area is considered to be an anisotropic unconfined aquifer with saturated thickness of 19.8 m. In order to characterize this aquifer pumping test was conducted, and the resulting drawdown data were utilized for the analysis by applying both type curve matching technique and semi-log straight line method. As a result, the average specific yield of this aquifer is estimated as 32.3%, and the average ratio of $K_H$ to $K_V$ is only 2.7, which means that gravitational effect is not significant factor for this type of aquifer. For the validation of the estimated hydraulic properties, the analytical model which was developed with Newton-Raphson iteration procedure in this study, was employed to generate the drawdown. And, the resulting drawdown was compared against actual drawdown data and it shows the excellent matches. The actual drawdown data for 9 hours of pumping were used for history matching purposes and relatively satisfactory matches were achieved in this match. Then, the model was run by using the tuned parameters that are obtained during history matching stage, and the drawdown was predicted for the next 30 years of pumping with $3,000m^3/day$ of constant pumping rate. Its result indicates that the drawdown was stabilized as 1.41 m from 20 days with $3,000m^3/day$ of constant pumping rate, which is the required amount of water to be safely supplied to this area.

• 디지털콘텐츠학회 논문지
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• 제5권4호
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• pp.251-256
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• 2004

반도체 집적회로를 만드는 토대가 되는 실리콘 웨이퍼의 표면은 고품질 회로를 구성하기 위해 극도의 평탄도가 요구되므로 평탄도는 양질의 웨이퍼를 보증하는 가장 중요한 요소이다. 따라서 실리콘웨이퍼 생산의 10개의 공정 중 거칠어진 웨이퍼 표면을 고도의 평탄도를 갖도록 연마하는 폴리싱공정은 매우 중요시 되는 생산라인이다. 현재 이 공정에서는 담당 엔지니어가 웨이퍼의 모형을 측정장비의 모니터에서 육안으로 관찰하여 판단하고 평탄도를 높이기 위한 제어를 하고 있다. 그러나 사람에 의한 것이므로 많은 경험이 필요하고 일일이 체크해야하는 번거로움이 있다. 본 연구는 이러한 비효율적인 작업의 효율화를 위해 웨이퍼의 모형을 디지털 컨텐츠화하여 폴리싱 공정에 있어 평탄도를 사람이 아닌 시스템에 의해 자동으로 측정하여 제어하는 알고리즘을 제안한다. 또한 제안한 전체 웨이퍼 평탄도 추정알고리즘을 토대로 실제 현장에서 쓰이는 웨이퍼 각 사이트별 평탄도를 측정하기 위한 사이트두께 추정 알고리즘을 제안한다.

• 한국미생물·생명공학회지
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• 제16권4호
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• pp.282-286
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• 1988

Chinese Hamster Ovary 세포의 대량배양을 위한 동력학적 변수들을 산소 소비속도의 on-line 측정으로 구하였다. 세포성장과 산소 소비속도의 상관관계 계수가 0.83으로 밀접한 상호 직선관계가 있음을 입증하며, 이에 근거를 둔 model에 의해 간접 계산된 세포수가 실제 측정된 세포수와 상당히 일치하였다. 따라서 세포끼리 서로 뭉쳐 직접 세포수 측정이 부정확한 경우 산소 소비속도의 측정에 의해 간접적으로 세포수를 예측할 수 있음을 입증하였다. 산소 세포수율, Yx/o와 mass transfer coefficient, $K_{\ell}$a가 각각 1.26$\times$$10^4$cells/mmole $O_2$ consumed와 1.011/h로 측정되었으며, 평균 세포 성장속도는 2.891/day로 계산되었다. 이는 매일 2 gram의 tPA를 연속 생산할 수 있는 조건이었다.