• 한국전기전자재료학회논문지
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• 제20권4호
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• pp.325-331
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• 2007

In this study, the inter-metal dielectric material of FSG was changed by low-k material in $0.13{\mu}m$ foundry-compatible technology (FCT) device process based on fluorinated silicate glass (FSG). Black diamond (BD) was used as a low-k material with a dielectric constant of 2.95 for optimization and yield-improvement of the low-k based device process. For yield-improvement in low-k based device process, some problems such as photoresist (PR) poisoning, damage of low-k in etch/ash/cleaning process, and chemical mechanical planarization (CMP) delamination must be solved. The PR poisoning was not observed in BD based device. The pressure in CMP process decreased to 2.8 psi to remove the CMP delamination for Cu-CMP and USG-CMP. $H_2O$ ashing process was selected instead of $O_2$ ashing process due to the lowest condition of low-k damage. NE14 cleaning after ashing process lot the removal of organic residues in vias and trenches was employed for wet process instead of dilute HF (DHF) process. The similar-state of SRAM yield was obtained in Cu/low-k process compared with the conventional $0.13{\mu}m$ FCT device by the optimization of these process conditions.

• International Journal of Quality Innovation
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• 제7권1호
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• pp.20-34
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• 2006

The purpose of this study is to investigate what happens within an organization when a process view of the business is adopted. With the example of an empirical case, we aim to illustrate: how members of the organization make sense of process management; what contributions members of the organization consider to be the result of adopting a process view; and the relationship between the functional and the process structure. The empirical base in this study is one of Sweden's largest purchasing organizations within the public sector. The results are drawn from interviews with the process owners and a survey to all members involved in process teams. The case findings reveal an ambiguous image of process management. At the same time as process management solved specific organizational problems, it generated new dilemmas. It is argued that it is more rewarding to consider the adoption of the process view a 'social negotiation' rather than the result of planned implementation. The study also highlights that the meaning of process management is not anything given but something being created, and its negotiation and translation into organizational practice is open-ended. Furthermore, the study gives an illustration of the conflict between the adopted process view and the existing functional organization.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.201-204
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• 2008

In this paper, several process parameter studies of the manufacturing process of the steel cords are carried out to verify the relation between the process parameters and the residual stresses on the steel cords. At first, the finite element analysis of the drawing process is performed and the residual stress distributions with respect to the wire material and the area reduction ratio are obtained. The residual stress of the drawn wire is imported the finite element analysis of the twisting process as an initial stress. After that a parameter study of the twisting process is carried out. The process parameters are the applied tension, the over-twisting angle and the tensile strength of the drawn wire. Based on these studies, the optimum values of the process parameters which can remove or reduce the undesired residual stresses are determined. The optimum value of the process parameters are confirmed by the finite element analysis of the elastic recovery process of the steel cords. Finally, the finite element analysis of the roller straightening process is done to study the variation of the distribution of the residual stress before and after the process.

• 한국산업정보학회논문지
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• 제15권1호
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• pp.47-57
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• 2010

다품종 소량생산 공정에서는 동일 특성을 가지는 제품의 제작 개수가 절대적으로 적기 때문에 전통적인 공정제어 기법인 통계적 공정관리(Statistical Process Control)를 적용하기에는 어려움이 많이 존재한다. 그러므로 통계적인 접근법과 아울러 다양한 제품 특성을 규정짓기 위한 다양한 조건의 조합으로 이루어지는 SPEC규칙, 그리고 엔지니어의 경험에 기반한 노하우가 응집되어 있는 KNOWHOW규칙을 유연하게 설정하여 공정을 제어할 수 있는 규칙기반 공정관리 기술의 접목이 필요하다. 본 연구는 다품종 소량생산 공정에 적용 가능한 규칙기반 공정관리(Rule-based Process Control) 시스템을 제안하고, 이 시스템을 실제 반도체 생산 공정에 적용하여 그 성과를 검증하였다.

• 품질경영학회지
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• 제41권4호
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• pp.725-735
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• 2013

Purpose: The purpose of this study is to propose an Integrated Safety Evaluation Process (ISEP) that can enhances the safety aspect of the safety-critical system. This process utilizes the advantages of the iterative Systems Engineering process combined with the safety assessment process that is commonly and well defined in many standards and/or guidelines for railway, aerospace, and other safety-critical systems. Methods: The proposed process model is based on the predefined system lifecycle, in each phase of which the appropriate safety assessment activities and the safety data are identified. The interfaces between Systems Engineering process and the safety assessment process are identified before the two processes are integrated. For the integration, the elements at lower level of Systems Engineering process are combined with the relevant elements of safety assessment process. This combined process model is represented as Enhanced Functional Flow Block Diagram (EFFBD) by using CORE(R) that is commercial modelling tool. Results: The proposed model is applied to the lifecycle and management process of the United States aircraft system. The US aircraft systems engineering process are composed of twelve key elements, among which the requirements management, functional analysis, and Synthesis processes are considered for examplenary application of the proposed process. To synchronize the Systems Engineering process and the safety assessment process, the Systems Engineering milestones are utilized, where the US aircraft system has thirteen milestones. Taking into account of the nine steps in the maturity level, the integrated process models are proposed in some phases of lifecycle. The flows of processes are simulated using CORE(R), confirming the flows are timelined without any conflict between the Systems Engineering process and the safety assessment process. Conclusion: ISEP allows the timeline analysis for identifying activity and data flows. Also, the use of CORE(R) is shown to be effective in the management and change of process data, which helps for the ISEP to apply for the development of safety critical system. In this study, only the first few phases of lifecyle are considered, however, the implementation through operation phases can be revised by combining the elements of safety activities regarding those phases.

• 한국산학기술학회논문지
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• 제14권12호
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• pp.6590-6596
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• 2013

Dimethyl Ether(DME) 제조공정에서 DME의 생산성을 높이기 위해서 이산화탄소를 반드시 제거해야 한다. 본 연구에서는 물리적 흡수제를 사용해서 이산화탄소를 제거할 수 있는 용매 흡수법과 막 분리법을 이용하여 이산화탄소를 제거하는 공정에 대해서 전산모사를 수행한 후, 공정 사이의 에너지 소모량을 비교하였다. 물리적 흡수제로는 메탄올을 사용한 Rectisol 공정, dimethyl ethers of polyethylene glycol를 사용한 Selexol 공정 및 N-methyl pyrrolidone를 사용한 Purisol 공정을 적용하였다. 전산모사를 수행하여 각 공정에서 소모된 에너지를 비교해 본 결과 Purisol 공정에서의 소요 동력이 Membrane 공정에 비해 97.55%, Rectisol 공정에 비해 91.71%, Selexol 공정에 비해 58.25% 감소하는 것을 알 수 있었다. 그러므로 DME 제조공정에 가장 적합한 이산화탄소 제거공정은 Purisol 공정이라 판단된다.

• 상하수도학회지
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• 제27권6호
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• pp.771-778
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• 2013

Gas hydrate (GH) process is a new desalination technology, where GH is a non- stoichiometric crystalline inclusion compounds formed by water and a number of gas molecules. Seawater GH is produced in a low temperature and a high pressure condition and they are separated from the concentrated seawater. The drawback of the GH process so far is that salt contents contained in its product does not meet the fresh water quality standard. This means that the GH process is not a standalone process for seawater desalination and it needs the help of other desalting process like reverse osmosis (RO). The objective of this study is to investigate the effect of GH process on energy saving for RO process in seawater desalination. The GH product water quality data, which were obtained from a literature, were used as input data for RO process simulation. The simulation results show that the energy saving effect by the GH process is in a range of 68 % to 81 %, which increases as the salt removal efficiency of the GH process increases. Boron (B) and total dissolved solids (TDS) concentrations of the final product of the hybrid process of GH and RO were also investigated through the RO process simulation to find relavant salt rejection efficiency of the GH process. In conclusion, the salt rejection efficiency of the GH process should exceed at least 78% in order to meet the product water quality standards and to increase the energy saving effect.

• 인터넷정보학회논문지
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• 제19권6호
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• pp.83-89
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• 2018

워크플로우 프로세스 인텔리전스와 시스템에서 워크플로우 프로세스 마이닝 및 분석 문제가 중요해지고 있다. 워크플로우 프로세스 인텔리전스의 품질을 향상시키기 위해서는 워크플로우 프로세스 마이닝 및 분석을 수행할 때, 워크플로우 실행 이벤트 로그를 저장하는 효율적이고 효과적인 데이터 센터가 필수적이다. 본 논문에서는 워크플로우 이벤트 로그 데이터 센터를 효율적으로 구성하고 XES 형식으로 워크플로우 프로세스 실행 이벤트 로그를 효과적으로 저장하기 위한 3차원 프로세스 기반 데이터 큐브를 제안한다. 이의 검증 단계로서, 프로세스 기반 데이터 큐브가 워크플로우 프로세스 패턴과 해당 워크플로우 프로세스 실행 이벤트 내역에서 실행 비율 및 업무전달관계와 같은 분석적 지식을 발견하는데 얼마나 적합한지를 보여주기 위해 프로세스 마이닝 실행 예제를 제시한다. 결과적으로, 프로세스 기반 데이터 큐브와 이를 활용한 프로세스 마이닝 시스템의 구현을 통해, 워크플로우 프로세스의 기본적 제어흐름 패턴을 성공적으로 발견할 수 있음을 확인했다.

• 한국물환경학회지
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• 제37권6호
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• pp.433-441
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• 2021

The aim of this study was to optimize the ozonation and ceramic membrane integrated process for greywater reclamation. The integrated process is a repeated sequential process of filtration and backwash with the same ceramic membrane. Also, this study used ozone and oxygen gas for the backwashing process to compare backwashing efficiency. The study results revealed that the optimum filtration and backwash time for the process was 10 minutes each when comparing the filtrate flow and membrane recovery rate. The integrated process was operated at three different operating conditions with i) 10 minutes for filtration and 10 minutes for ozonation, ii) 10 minutes for filtration and 10 minute for oxygen aeration, and iii) continuous filtration without any aeration for synthetic greywater. The integrated process with ozone backwashing could produce 0.55 L/min of filtrate with an average of 18.42% permeability recovery, while the oxygen backwashing produced 0.47 L/min and 6.26%, respectively. And without any backwashing, the integrated process could produce 0.29 L/min. This shows that the ozone backwash process is capable of periodically recovering from membrane fouling. The resistance of the fouled membrane was approximately 34.4% for the process with ozone backwashing, whereas the resistance was restored by 10.8% for the process with oxygen backwashing. Despite the periodical ozone backwashing and chemical cleaning, irreversible fouling gradually increased approximately 3 to 4%. Approximately 97.6% and 15% turbidity and TOC were removed by ceramic membrane filtration, respectively. Therefore, the integrated process with ozonation and ceramic membrane filtration is a potential greywater treatment process.

• 대한수학회논문집
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• 제12권3호
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• pp.725-741
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• 1997

This paper considers the problem of deriving exponential probability inequalities for product symmetric Poisson processes. As an application they are used to show the existence of regular version of some product process derived from L$\acute{e}$vy process.